36. Mariana Trench, Pacific Ocean

Off the coast of Japan and the Philippines is what we know as the deepest trench in the ocean. The trench is over 7-miles deep, and the pressure is extreme as you get deeper. Bubbles of sulfur and carbon dioxide make their way up from the bottom, and it's pretty apparent why this place is off-limits. 

Although 80 percent of the ocean is still unexplored, this is the deepest point researchers have found. The pressure at the bottom of the trench is equivalent to having a jumbo jet sitting on top of you, which doesn't make for a relaxing vacation. It's best to go somewhere else.