New Delhi: Travelling by train can be the most relaxing, and you could well undertake the most scenic journeys. But with steep climbs on almost-vertical hills, zig-zagging tracks on cliff faces, or narrow bridges over cyclone-prone, high-wind locations, some train rides can get your heart pounding a little bit faster and harder. Steep climbs, creaky trestles, and cliff-hugging curves are part of the ride on these rail routes.Here, we explore the most memorable railways routes in the world: 1. Tren a las Nubes, Argentina View of the La Polvorilla viaduct in Salta Province, Argentina. The Train a las Nubes (or Train to the Clouds) runs through the viaduct and connects the Argentine Northwest with the Chilean border in the Andes mountain range 13,850 ft above mean sea level. 2. White Pass and Yukon Route Railroad, Alaska The White Pass and Yukon Route is a narrow gauge railroad linking the port of Skagway, Alaska, with Whitehorse, the capital of Yukon. Completed in 1900, the railroad makes a number of cliff-hanging turns. 3. Rameswaram Express, India The Pamban Bridge is a one-and-a-half-mile cantilever bridge on the Palk Strait that connects Rameswaram on Pamban Island to mainland India. The location of the bridge is a cyclone-prone, high wind velocity zone. 4. Outeniqua Choo-Tjoe Train, South Africa Completed in 1928, the Outeniqua Choo Tjoe connected the towns of George and Knysna in South Africa's Western Cape. The scenic 42-mile route hugs the rugged coastline of the Garden Route before ending by crossing a bridge over the lagoon in Knysna. 5. Minamiaso Railway, Tateno Bridge, Japan The Minamiaso Railway crossing the Tateno Bridge. The line runs the south part of Mount Aso caldera, one of the largest volcanic calderas in the world. 6. Georgetown Loop Railroad, Colorado A narrow gauge heritage railroad located in the Rocky Mountains in Clear Creek County, Colo., the Georgetown Loop Railroad ascends an elevation of 640 feet through mountainous terrain along with trestles, cuts, fills, and a grand loop. 7. Kuranda Scenic Railway, Australia The Kuranda Scenic Railway runs from Cairns, Queensland, Australia to the nearby town of Kuranda. The line runs through the Barron Gorge National Park, and past waterfalls and tunnels.8. Nariz del Diablo, Ecuador The Nariz del Diablo or 'Devil's Nose' train travels the central highlands of Ecuador. Although no longer allowed due to recent accidents, passengers used to ride on the roof of the train to enjoy the best views of mountains and rivers. 9. Burma-Thailand Railway The Burma Railway, also known as the Death Railway, is a railway between Bangkok, Thailand, and Rangoon, Burma (now Yangon, Myanmar). The train hugs the sides of sheer cliffs, and passes over a number of rickety wooden bridges. 10. Glenfinnan Railway Viaduct, Scotland It was built between July 1897 and October 1898 at the cost of £18,904. Located at the top of Loch Shiel in the West Highlands of Scotland, the viaduct overlooks the Glenfinnan Monument and the waters of Loch Shiel.