Archeologists have uncovered remnants of many ancient board games from civilizations around the world. These include Liubo, a two player game from China's Han Dynasty dating back to around 1800 BCE. Ancient games have also been found from the Bronze Age consisting of small stone pieces, and a 3000 BCE board game called "Game of 20 Squares" originating in Sumer. Additionally, the Aztec empire played the gambling game "patolli", while the Chinese strategy game "Go" began up to 4000 years ago and is still played today.