1) The blue whale is the largest animal to have ever existed, with an average length of about 82 feet (25 meters).

2) The world's longest traffic jam occurred in China in 2010 and lasted for 12 days, stretching over 60 miles (97 km).

3) The word "mountain" contains three vowels: O, U, and A.

4) 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.