1) 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.

2) The Black Lives Matter movement, which gained prominence in 2013, advocates for racial justice and equality, addressing systemic racism and police violence against Black individuals.

3) The United Nations Security Council is responsible for maintaining international peace and security, with five permanent members (China, France, Russia, the United Kingdom, and the United States) holding veto power over resolutions.

4) In Norse mythology, Valhalla is a majestic hall located in Asgard, the realm of the gods. It is the afterlife destination for brave warriors who die in battle, where they are greeted by the Valkyries and engage in feasting, drinking, and preparing for the final battle of Ragnarok.