1) The Great Wall of China is a UNESCO World Heritage site and one of the most iconic man-made structures in the world. It stretches over 21,196 kilometers (13,171 miles) and was constructed to protect the Chinese empire from invasions during ancient times.

2) The Hubble Space Telescope, launched in 1990, has provided breathtaking images of distant galaxies and deep space.

3) The word "triangle" contains four vowels: I, A, E, and E.

4) The Triple Double in basketball refers to a player achieving double-digit totals in three of the following statistical categories: points, rebounds, assists, steals, or blocks.