The Russian capital Moscow is celebrating its 870th birthday. Hundreds of exciting events got off to a start at more than 40 venues on Saturday to mark the City Day. These include extreme sports, a street theater festival, and a food festival. The city has become one of the most modern in the world. President Vladimir Putin spoke at Red Square. He said Moscow is putting its efforts into improving the quality of life. The capital is also a major national economic, cultural, and scientific center. The earliest recorded mention of Moscow was in 1147, which means it could be older than 870.