The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country of Panama and the Panama Canal. Like many isthmuses, it is a location of great strategic value. 

Site of the practical joke hold-up.

Gold Hill is an unincorporated community in Storey County, Nevada, located just south and downhill of Virginia City. Incorporated December 17, 1862, in order to prevent its annexation by its larger neighbor, the town at one point was home to at least 8,000 residents. Prosperity was sustained for a period of 20 years between 1868 and 1888 by mining the Comstock Lode, a major deposit of gold and silver ore. Mines such as the Yellow Jacket, Crown Point, and Belcher brought in over $10 million each in dividends. The Gold Hill post office remained in operation until 1943.

Kīlauea (/kiːlaʊˈeɪ.ə/; Hawaiian: [ˈkiːlɔuˈwɛjə]) is a currently hyperactive shield volcano in the Hawaiian Islands, and the most active of the five volcanoes that together form the island of Hawaiʻi, and, perhaps, the most active volcano on earth. Located along the southern shore of the island, the volcano, at 300,000 to 600,000 years old and going above sea level about 100,000 years ago, it is the second youngest product of the Hawaiian hotspot and the current eruptive center of the Hawaiian–Emperor seamount chain.

Kealakekua Bay is located on the Kona coast of the island of Hawaiʻi about 12 miles (19 km) south of Kailua-Kona. Settled over a thousand years ago, the surrounding area contains many archeological and historical sites such as religious temples, and was listed in the National Register of Historic Places listings on the island of Hawaii in 1973 as the Kealakekua Bay Historical District. The bay is a marine life conservation district, a popular destination for kayaking, scuba diving, and snorkeling.

Angels Camp, also known as City of Angels and formerly Angel's Camp, Angels, Angels City, Carson's Creek and Clearlake, is the only incorporated city in Calaveras County, California, United States. The population was 3,835 at the 2010 census, up from 3,004 at the 2000 census. It lies at an elevation of 1378 feet (420 m). 

This site is located four miles north of Fairbury, in Jefferson County, Nebraska. Other names for the station include Grayson's and Whiskey Run.  Bishop and Henderson identify the station as Virginia City on their "Map of California- Oregon-Mormon Emigrant Roads Featuring the Pony Express 1860-1861," as does trail historian Gregory M. Franzwa.  Lone Tree possibly served as an alternate station site, one mile south of Virginia City. http://www.nps.gov/parkhistory/online_books/poex/hrs/hrs4c.htm#16

Mono Lake (moʊnoʊ/ moh-noh) is a large, shallow saline soda lake in Mono County, California, formed at least 760,000 years ago as a terminal lake in an endorheic basin. The lack of an outlet causes high levels of salts to accumulate in the lake. These salts also make the lake water alkaline.  http://en.wikipedia.org/wiki/Mono_Lake

 J.M Corey, James N Braley, and E.R Hicks founded the town in 1860. At one point it had a population of around 10,000. Aurora's mines produced $27 million worth of gold by 1869. The town was governed by both California and Nevada until it was determined that the town lay entirely in Nevada. At one point it was simultaneously the county seat of both Mono County, California and Esmeralda County, Nevada. Its California assemblyman was the speaker of the house while the Nevada legislative member was elected as president of the Nevada Territorial Legislature.

"The Humboldt (Imlay, Eldorado) district, on the north end and west flank of the Humboldt Range, was organized in 1860 as the first district in the area now included in Pershing County. By 1863, Humboldt City had been founded and had a population of 500. The principal mine was the Imlay, from which a considerable but unknown amount of silver ore was shipped. The Star Peak mine yielded $130,000 in silver and gold up to 1935 (Vanderburg, 1936b, p. 17).

Government House, Melbourne is the office and official residence of the Governor of Victoria. It is set next to the Royal Botanic Gardens and surrounded by Kings Domain in Melbourne. It was the official residence of the Governor-General of Australia from 1901 to 1930. It is the largest Government House in the former British Empire and is almost double the size of the Viceregal Lodge, the former residence of the Lords-Lieutenant of Ireland.  http://en.wikipedia.org/wiki/Government_House,_Melbourne

The point on the map is actually the location of St Paul's Cathedral.  

Situated at the south-east corner of Bourke and William streets, Menzies Hotel was the first of Melbourne's grand hotels and certainly one of the finest. In 1872 English author Anthony Trollope noted that he had never stayed 'at a better inn in any part of the world'. The site was purchased in 1867 by Mr and Mrs Archibald Menzies whose Menzies Family Hotel in La Trobe Street dated from 1853. Designed by Reed & Barnes and constructed at a cost of £32 000 by David Mitchell, the three-storey building with columned arcade and pavilion towers opened in November 1867.

Southern Cross (formerly and still colloquially known, as Spencer Street) is a major railway station in Docklands, Melbourne. It is on Spencer Street, between Collins and La Trobe Streets, at the western edge of the central business district. The Etihad Stadium sports arena is 500 metres north-west of the station. http://en.wikipedia.org/wiki/Southern_Cross_railway_station 

Designed by architects Reed & Barnes, this theatre opened as the Academy of Music in Bourke Street in November 1876 under the management of G.B.W. Lewis. Renamed the Bijou in 1880, it shared the site with the Palace Hotel from 1888. After the theatre was destroyed by fire in 1889, George Johnson designed a larger, more sumptuous building in 1890, at which time the hotel's multi-purpose hall was transformed into the Gaiety Theatre, which operated as a music hall.

Mark Twain lectured at the Bijou Theatre in Melbourne five (5) times, Friday, September 27, 1895, Saturday, September 28, Monday, September 30, Tuesday, October 1, and Wednesday, October 2. He returned to Melbourne in late October and lectured once at the Athenaeum Hall on Saturday, October 26, 1895.

Wagga Wagga (/ˈwɒɡəˈwɒɡə/[4] wog-ə wog-ə; informally called Wagga) is a city in New South Wales, Australia. Straddling the Murrumbidgee River, with an urban population of 46,913 people,  Wagga Wagga is the state's largest inland city,  and is an important agricultural, military, and transport hub of Australia. It is midway between the two largest cities in Australia, Sydney and Melbourne, and is the major regional centre for the Riverina and South West Slopes regions.  http://en.wikipedia.org/wiki/Wagga_Wagga 

The Blue Mountains is a mountainous region in New South Wales, Australia. It borders on Sydney's metropolitan area, its foothills starting about 50 kilometres (31 mi) west of the state capital. The public's understanding of the extent of the Blue Mountains is varied, as it forms only part of an extensive mountainous area associated with the Great Dividing Range.

Seymour (/ˈsiːmɔr/, locally [ˈsiːmoː]) is a township in Mitchell Shire in the state of Victoria, Australia and is located 98 kilometres (61 mi) north of Melbourne. At the 2011 census, Seymour had a population of 6,360. The township services the surrounding agricultural industries (primarily equine, cattle, sheep and wine) as well as the nearby military base of Puckapunyal (population 1,176), which is an important training centre for the Australian Army.

Albury /ˈɔːlbəri is a major regional city in New South Wales, Australia, located on the Hume Highway on the northern side of the Murray River. It is the seat of local government for the council area which also bears the city's name - the City of Albury. Albury has an urban population of 45,627 people. 

Twain is supposed to have ‘spent many pleasant hours during his too- short stay’ fishing with J.F. Archibald at his Cronulla cottage” [“Down Under” 8]. (Editorial emphasis.) Mark Twain Day by Day, September 21-24, 1895  

Cronulla is a beachside suburb, in southern Sydney, in the state of New South Wales, Australia. Cronulla is located 26 kilometres south of the Sydney central business district, in the local government area of the Sutherland Shire.  

Bondi Beach or Bondi Bay (/ˈbɒndaɪ/ bon-dye) is a popular beach and the name of the surrounding suburb in Sydney, New South Wales, Australia. Bondi Beach is located 7 km (4 mi) east of the Sydney central business district, in the local government area of Waverley Council, in the Eastern Suburbs. Bondi, North Bondi and Bondi Junction are neighbouring suburbs. http://en.wikipedia.org/wiki/Bondi_Beach,_New_South_Wales

Admiralty House is the official Sydney residence of the Governor-General of Australia. It is located in the suburb of Kirribilli, on the northern foreshore of Sydney Harbour (adjacent to Kirribilli House, which is the Sydney residence of the Australian Prime Minister). This large, Italianate, sandstone mansion occupies the tip of Kirribilli Point. Once known as "Wotonga", it has commanding views across Sydney Harbour to the Sydney Harbour Bridge and the Sydney Opera House. 

In 1835 the British government agreed that a new Government House in Sydney had become a necessity, and the royal architect, Edward Blore, was instructed to draw up plans. Construction commenced in 1837 and was supervised by colonial architect Mortimer Lewis and Colonel Barney of the Royal Engineers. Stone, cedar, and marble for the construction were obtained from various areas of New South Wales. A ball in honour of the birthday of Queen Victoria was held in the new building in 1843, although construction was not complete.

The first farm on the Australian continent, at Farm Cove, was established in 1788 by Governor Phillip. Although that farm failed, the land has been in constant cultivation since that time, as ways were found to make the relatively infertile soils more productive.

On 29 April 1770, Botany Bay was the site of James Cook's first landing of HMS Endeavour on the continent of Australia, after his extensive navigation of New Zealand. Later the British planned Botany Bay as the site for a penal colony. Out of these plans came the first European habitation of Australia at Sydney Cove. Even though the penal settlement was almost immediately shifted to Sydney Cove, for some time in Britain transportation to "Botany Bay" was a metonym for transportation to any of the Australian penal settlements.

455 George St, Sydney NSW 2000, Australia

From Mark Twain Day By Day:  "Around noon Sam invited the Sydney Daily Telegraph reporter to go with him to be photographed at Falk’s Studio, owned by H. Walter Barnett. Shillingsburg writes that while at the studio Sam made  “remarks on protectionism that would provoke an angry diatribe the next afternoon [Sept. 17] from a rival paper, the Australian Star.”  Note: World Tour Info. Sources: Shillingsburg, Railton, Lorch, MTHHR, Fatout, MTJ: Shillingsburg, Ahluwalia, Philippon" 

Sydney Cove, on which Circular Quay is located, was the site of the initial landing of the First Fleet in Port Jackson on 26 January 1788. In 1794 Thomas Muir, a Scottish constitutional reformer, was sentenced to transportation for sedition. Thomas Muir purchased Lightfoot's farm. Muir also had a cottage on what is now Circular Quay. It is likely that the farm was located at the Jeffrey Street end of Kirribilli (not near Admiralty house) and was named "Huntershill" by Thomas Muir, after his father’s home in Scotland.

The Australia Hotel in Castlereagh Street, Sydney, was until its closure on 30 June 1971, "the best-known hotel in Australia",  "the premier hotel in Sydney" and described itself as "The Hotel of the Commonwealth". Situated in one of Sydney's important thoroughfares in the heart of the city, the foundation stone was laid by Sir Henry Parkes in 1889, and the opening of the new establishment was performed two years later by Sarah Bernhardt, whose name was first in the new hotel's register, subsequently displayed in a glass showcase in the main foyer.

The Town Hall was built in the 1880s – on the site of an old cemetery – from local Sydney sandstone in the grand Victorian Second Empire style, and has been described as having "lavishly ornamented composition with focal tower and fanciful roofs". It remains the only non-religious city building from the era to retain its original function and interior. The building houses the Sydney City Council Chamber, reception rooms, the Centennial Hall and offices for the Lord Mayor and elected councillors.

The Domain is 34 hectares of open space in Sydney, New South Wales, Australia. It is located on the eastern edge of the Sydney central business district, near Woolloomooloo. The Domain adjoins the Royal Botanic Gardens and is managed by the Royal Botanic Gardens Trust, a division of the Office of Environment and Heritage. It is a popular venue for outdoor concerts, open air events and for large gatherings and rallies. http://en.wikipedia.org/wiki/The_Domain,_Sydney

This seems to be the most likely location for Cooper's Wharf, on Cowper Wharf Road.  Finger Wharf  Woolloomooloo NSW 2011, Australia

Her Majesty's Theatre, Sydney, Australia, refers to three theatres of the same name:  

One was a theatre which opened on 10 September 1887 and closed on 10 June 1933. It was located on the corner of Pitt and Market Street, Sydney, where Centrepoint stands today. 

The second was located in Quay Street. It had opened with the show "Sunny" in 1927 as the Empire Theatre. When J.C. Williamson wanted a long run for My Fair Lady, they renamed the theatre Her Majesty's. The theatre barely survived the 1960s and was destroyed by fire.  

Mrs Macquarie's Chair (also known as Lady Macquarie's Chair) is an exposed sandstone rock cut into the shape of a bench, on a peninsula in Sydney Harbour, hand carved by convicts from sandstone in 1810 for Governor Macquarie's wife Elizabeth. The peninsula itself is named Mrs Macquarie's Point, and is part of the The Domain, near the Royal Botanic Gardens. 

http://www.michaelsmithnews.com/2012/12/for-sydneysiders-ever-wondered-about-the-old-australian-workers-union-building-in-castlereagh-street.html

Mark Twain lectured here four (4) times in September 1895, Thursday the 19th, Saturday the 21st, Monday the 23rd, and Tuesday the 24th.

http://news.google.com/newspapers?id=LmlVAAAAIBAJ&sjid=PpUDAAAAIBAJ&pg=3162%2C3728108

Wednesday, September 18, 1895, Mark Twain gave a toast: Advance Australia