1) The total length of your blood vessels can circle the Earth more than twice.

2) The world's largest desert is the Sahara Desert in Africa, covering an area of about 3.6 million square miles (9.4 million square kilometers).

3) The Great Barrier Reef, situated off the coast of Queensland, Australia, is the largest coral reef system in the world. It stretches over 2,300 kilometers (1,400 miles) and is home to a diverse array of marine life, making it a popular destination for diving and snorkeling.

4) The Mongol Empire, under the leadership of Genghis Khan, became the largest contiguous empire in history, spanning from Asia to Europe.