1) The construction of the Great Wall of China began in the 7th century BC and was completed over several centuries, spanning thousands of miles.

2) The Great Wall of China is not visible from space without aid, contrary to popular belief.

3) The fastest recorded serve in tennis was achieved by Sam Groth at 163.7 miles per hour (263.4 kilometers per hour) during a tournament in 2012.

4) The longest-running TV show in history is "The Simpsons," which has been on the air since 1989 and has over 700 episodes.