1) 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.

2) The world's largest flower is the Rafflesia arnoldii, which can grow up to 3 feet (1 meter) in diameter and weighs about 15 pounds (7 kilograms).

3) The first computer mouse was invented by Douglas Engelbart in 1964 and consisted of a wooden shell and two metal wheels.

4) The Battle of Waterloo in 1815 marked the final defeat of Napoleon Bonaparte and the end of his reign as Emperor of France.