1) The term "bull market" refers to a period of rising stock prices, while a "bear market" refers to a period of falling stock prices.

2) 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.

3) Mount Kilimanjaro in Tanzania is the highest mountain in Africa and attracts climbers from around the world.

4) The first commercially successful video game was "Pong," released in 1972 by Atari.