1) Celtic mythology encompasses the folklore and legends of the Celtic peoples across Europe, particularly in regions like Ireland, Scotland, and Wales. It features deities like Morrigan, Cernunnos, and Brigid, and delves into themes of nature, magic, and the heroic exploits of legendary figures like Cu Chulainn.

2) The Bugatti Veyron, one of the fastest production cars in the world, can reach speeds of over 250 miles per hour (402 km/h).

3) The fall of the Berlin Wall in 1989 symbolized the end of the Cold War and the reunification of East and West Germany.

4) The sitcom "Friends" is known for its iconic Central Perk coffee shop, where the main characters often gather.