Niagara Falls is a natural wonder, but it is not a UNESCO World Heritage Site.

The Great Barrier Reef is the largest coral reef system in the world, stretching for over 2,300 kilometers along the coast of Queensland, Australia.

Mediterranean Rainforest is not a type of rainforest. It is a type of forest found in regions with a Mediterranean climate.

Mount Everest is the highest mountain in the world, with a peak elevation of 8,848.86 meters (29,031.7 feet) above sea level.

Antarctic Desert is not a major desert in the world. It is a cold desert located in Antarctica.

Angel Falls is the largest waterfall in the world, with a height of 979 meters (3,212 feet) and a plunge of 807 meters (2,648 feet).

Mississippi River is not a major river in the world. It is a major river in North America.

Caspian Sea is the largest lake in the world by surface area, covering an area of 371,000 square kilometers (143,244 square miles).

Rocky Mountains is not a major mountain range in the world. It is a major mountain range in North America.

Greenland is the largest island in the world, with an area of 2,166,086 square kilometers (836,330 square miles).

Korean Peninsula is not a major peninsula in the world. It is a peninsula located in East Asia.

Yarlung Tsangpo Grand Canyon is the largest canyon in the world, with a length of 504.6 kilometers (313.6 miles) and a depth of 6,008 meters (19,711 feet).

Mount Kilimanjaro is not a major volcano in the world. It is a major volcano in Africa.

Steamboat Geyser is the largest geyser in the world, with eruptions that can reach heights of over 90 meters (300 feet).

Phong Nha-Ke Bang National Park is not a major cave in the world. It is a national park in Vietnam that contains many caves.