36. Mount Everest
> Location: Nepal
The highest point on Earth, Mount Everest rises 29,035 feet above sea level. It sits on the border of Nepal and Tibet in the Himalayan mountains. While the death rate for Everest climbers is about 1 in 10, safer options for viewing the frozen peak include hiking along the Shigatse Valley or taking a helicopter tour around the mountain.
> Location: Turkey
Pamukkale, which means Cotton Castle in Turkish, is home to a series of warm turquoise pools framed by travertine limestone terraces. Mineral deposits from the flowing hot springs built up over millennia and formed the limestone pools, which visitors are permitted to dip in.
38. El Yunque
> Location: Puerto Rico
El Yunque National Forest is the largest section of public land in Puerto Rico, and the only tropical rainforest in the United States National Forest System. Heavy rainfall contributes to the area’s ample rivers and waterfalls, which are popular for swimming and photography.
> Location: Australia
Uluru is a massive, isolated, sandstone monolith famous for its bright red hue. It rises 1,142 feet from the surrounding desert and is nearly six miles in circumference. Uluru is sacred to the Aboriginal people of the area, and caves within the base of the stone contain ancient petroglyphs.
40. Mammoth Cave
> Location: Kentucky
The world’s longest known cave system, with over 400 miles of surveyed caverns, is in southern Kentucky. The network contains one of the highest diversities of cave-adapted organisms in the world.