Ice Tunnel In Rhone Glacier (Switzerland)
Rhone Glacier is said to be much older than 17th century. First entry into the glacier was through a thin tunnel.
Gateway to Heaven – Tianmen Cave, China
The mountain hairpin bends are from the the approaches to the Tianmen Mountain also known as Gate way to Heaven – Tianmen cave in China and is part of Wulingyuan Scenic Area – a UNESCO World Heritage Site.