Love train travel? These railways offer a unique window on the world, cutting a swath through some of the most breathtaking landscapes on Earth:

The steam trains climb the 11 miles (18 km) from Cass to the 4,842-ft-high (1,476 m) summit of Bald Knob, which has spectacular views and bracing mountain air. The line, built in 1901 to haul lumber, uses geared locomotives to overcome its ferocious gradients, which include switchbacks.

Planning: Advance booking is advisable. Bring plenty of warm clothing.

Built in 1898 during the Klondike Gold Rush, the narrow-gauge WP&YR starts from the Taiya Inlet quaysides of Skagway, Alaska, and climbs 2,880 ft (878 m) over the White Pass into Canada’s Yukon territories and some of the north’s most rugged terrain. Diesel and steam trains travel to Carcross or Fraser Meadows.

Planning: Passports are required. There are places to stay in Skagway, on the South Klondike Highway. Advanced booking is advisable.

Departing twice weekly from Esquel in Patagonia’s mountainous Chubut province, this antique train—known locally as La Trochita (“the little narrow gauge”)—winds through rugged terrain to the small settlement of Nahuel Pan.

Planning: The round-trip takes 2.5 hours. Accommodations are available in Esquel, reached by plane or bus from Buenos Aires.

4. The Overlander (North Island, New Zealand)

This epic 423-mile (681 km) train journey through the heart of North Island links Auckland in the north to Wellington in the south. Highlights along the way include the ski resort of National Park, the Mount Ruapehu volcano, the Raurimu Spiral, and the Hapuawhenua Viaduct. There is an observation carriage at the back of the train and a viewing platform at the front. On certain Sundays the train is steam-hauled for part of the near 12-hour journey.

Planning: The service runs daily in the summer season (except Christmas Day).

Snaking along the Queensland coast between Brisbane and Cairns, the Sunlander offers a superbly luxurious service with dining and sleeping-car facilities. As Queensland glides past the windows, passengers can enjoy local seafood platters or club and buffet-car fare. The climate becomes increasingly tropical as the train travels north toward Cairns.

Planning: The journey takes about 32 hours.

The train south from Kandy, in central Sri Lanka, to Haputale travels past tea plantations, forests, unspoiled villages, and waterfalls. For the five-hour journey, the first class observation car is well worth the extra fare.

Planning: Advance booking is essential. Expect high temperatures and humidity.

7. Malnad (Western Ghats, India)

Shimoga in India’s Karnataka province is the eastern end of the run to Talaguppa in the Western Ghat Mountains. The 46.6-mile (75 km), three-hour journey aboard a small railbus from Shimoga to Talaguppa passes through lush rain forest. The magnificent Jog Falls—India’s highest waterfall—can be reached by road from Talaguppa.

Planning: An overnight train from Bangalore connects with Shimoga. Facilities on the railbus are limited. The line is being upgraded, so check ahead before traveling.

8. Sarajevo to Mostar (Bosnia and Herzegovina)

Traversing superb Balkan scenery, the train from Sarajevo climbs to its highest point near Konjic, where it joins the Neretva Valley. The descent into Herzegovina passes through dramatic gorges until reaching the town of Mostar, famous for the 16th-century stone bridge that was destroyed during the Bosnian War in the 1990s and rebuilt.

Planning: The journey takes about 2.5 hours. There are two trains per day.

Opened in 1927, this miniature steam railway (its rails are just 15 in/38 cm apart) runs from the picturesque resort of Hythe to the shingle foreland of Dungeness, famous for its lighthouse, power station, and wildlife. Stops along the 13.5-mile (22 km) route include the seaside resort of Dymchurch with its miles of sandy beach.

Planning: There is a model railway exhibition at New Romney Station.

Running to Porthmadog Harbour Station from Caernarfon in North Wales’s Snowdonia National Park, this spectacular line traverses some of the finest scenery in Wales. Catch dramatic views of Snowdon’s 3,560-ft (1,085 m) summit and the precipitous Aberglaslyn Pass from the Pullman observation cars as the train blasts through the mountains.

Planning: Porthmadog and Caernarfon both have places to stay.