The Great Barrier Reef is the largest living structure on Earth and can be seen from outer space.
The human brain is the most complex organ in the body, containing over 100 billion neurons.
The tallest mountain in the world is Mount Everest, located in the Himalayas and reaching a height of 29,029 feet (8,848 meters).
The largest ocean in the world is the Pacific Ocean, covering an area of about 63.8 million square miles (165.25 million square kilometers).
The human body is made up of about 60% water.
The oldest known civilization is the Sumerian civilization, which emerged in Mesopotamia around 4500 BCE.
The first modern Olympic Games were held in Athens, Greece in 1896.
The United States is the third largest country in the world by land area, after Russia and Canada.
The fastest land animal is the cheetah, which can reach speeds of up to 70 miles per hour (112 kilometers per hour).