3. Valley of the Moon, San Juan, Argentina The Ischigualasto Formation, known as the Valley of the Moon, is a valley filled with strange clay formations --of all shapes and colors created by different layers of mineral and sediments. The strange rock formations have endearing nicknames, like the mushroom, the submarine and Alladin's lamp. The valley contains dinosaur fossils dating back as far as 225 million years ago, and in fact is the only place on earth where nearly all dinosaur fossils from the Triassic period can be found together. To visit, it is about a five hour drive from the provincial capital of San Juan City.