The Trulli houses of Alberobello in the Puglia region of Italy were built by settlers from limestone and not much else. An impressive dry stone building technique meant the houses could be collapsed simply by pulling out a keystone.
Australia's Amazing Bioluminescent Lake (Also Bioluminescent Bay in Puerto Rico). An unusually high concentration of Noctiluca scintillans, a bioluminescent microorganism, turned the water a bright, glowing, ethereal blue.
Kaieteur Falls - the world's largest drop waterfall. Located on the Potaro River in central Guyana, Potaro-Siparuni region in Kaieteur National Park. My grandad was from Guyana, would love to visit one day.