In Search of the Castaways: Captain Grant's 37th Parallel

The expedition is born in Scotland. Lord Glenarvan, of Malcolm Castle at Luss in Dumbartonshire, decides to search for Captain Grant himself after a bottle message turns up. When the crew of his yacht Duncan hear where they are bound, "the rocks of Dumbarton rang again with their joyous outbursts of cheers." Dumbarton Rock is a 240-foot basalt plug above the Clyde, topped by Dumbarton Castle.

Location precision: The novel names Dumbarton, not a quay; the pin marks Dumbarton Rock, the landmark on the Clyde.

Visitor guidance: Dumbarton Castle stands on the rock above the town.

Landfall in South America. The Duncan steams into the bay of Talcahuano, which Verne calls "a magnificent estuary, twelve miles long and nine broad." A chapter of the novel is set in this bay, which makes Talcahuano the Chilean stop of any Captain Grant's Children route.

Location precision: The pin marks the town of Talcahuano on its bay, not a specific spot in the chapter.

Visitor guidance: Talcahuano is a town on the bay.

The 37th parallel crosses the Atlantic, and Paganel argues that the Duncan should stop "a day or two at the Tristan d'Acunha Isles and the Amsterdam", since both lie on the route. The group explores Tristan da Cunha in search of the wrecked Britannia. In reality it is the most remote inhabited place in the world, and the only way to travel to or from Tristan is by ship.

Location precision: The pin marks the main island, not a landing place described in the book.

Next comes Amsterdam Island, which Verne places at 37 degrees 47 minutes of latitude and 77 degrees 24 minutes of longitude. Its high cone is visible fifty miles off in clear weather. The real island, part of the French Southern and Antarctic Lands, reaches 867 metres at Mont de la Dives. It is another stop on the 37th parallel where the searchers hope to find a trace of Captain Grant.

Location precision: The pin marks the island's centre; the book gives no landing spot.

Crossing Australia, the party hopes to camp on the banks of the Snowy River, "an important river which throws itself into the Pacific, south of Victoria." The real Snowy River rises on the slopes of Mount Kosciuszko, Australia's highest mainland peak, and runs through the Alpine National Park and the Snowy River National Park in Victoria before reaching Bass Strait.

Location precision: The novel gives the river's course, not one campsite; the pin marks the river in Victoria.

Visitor guidance: The Snowy River National Park in Victoria protects much of the river's course.

The search ends up on New Zealand's North Island, where the travellers end up as captives. At sunset the captives are led back to their prison, "just as the sun was sinking beyond Lake Taupo." In reality Lake Taupo is New Zealand's largest lake by surface area, a crater lake in the caldera of a volcano.

Location precision: The scene is placed near the lake; the pin marks the lake itself.

Visitor guidance: The town of Taupo lies on the lake's northeastern shore.

The Duncan sights "a low, elongated island, scarcely raised above the waves, and looking like an enormous whale." It is Maria Theresa on English charts and Tabor on French ones, and it shelters Captain Grant. Ayrton, the renegade, is left in Grant's place. The real Maria Theresa Reef appears to be a phantom reef: no island has been found there.

Location precision: The island in the book is invented; the pin marks the reef position Wikipedia lists, which probably does not exist.