1) The total length of your blood vessels can circle the Earth more than twice.

2) The name "Bluetooth" comes from the 10th-century Danish king, Harald Bluetooth, who united Denmark and Norway.

3) The world's oldest university, Al-Qarawiyyin, was founded in 859 AD and is located in Fez, Morocco.

4) Mount Everest, located in the Himalayas, is the highest peak on Earth, with an elevation of 8,848 meters (29,029 feet). It is a popular destination for mountaineers and represents a significant challenge due to its extreme altitude and harsh weather conditions.