"Lake Baikal in eastern Siberia is the oldest freshwater lake on Earth, and one of the largest and deepest, containing around one-fifth of the world's freshwater. In winter, it freezes over, and these beautiful transparent, turquoise masses of broken ice appear momentarily in March, caused by the unequal structure, temperature and pressure in the main body of the packed ice."
Spooky Gulch, south of Escalante, Utah. Travelers who are claustrophobic may want to avoid hiking Spooky Gulch. Passageways are so narrow in some places, hikers have to squeeze through sideways. It also can be quite dark on the canyon bottom. This canyon walk is 5 km (3.2 miles) roundtrip. Those who don’t want to go back the way they came can climb the canyon walls or continue on through Peek-a-boo Gulch, another beautiful slot canyon.