1) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.

2) The Sydney Opera House, situated in Sydney, Australia, is an iconic architectural masterpiece and a UNESCO World Heritage site. Its unique design, resembling sailboats or shells, has made it one of the most recognized and photographed landmarks in the world.

3) Mount Kilimanjaro in Tanzania is the highest mountain in Africa and attracts climbers from around the world.

4) The Great Lakes, consisting of Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, form the largest group of freshwater lakes on Earth by total area. They are shared by the United States and Canada and are of significant ecological and economic importance.