Seoul is first recorded as Wiryeseong, the capital of Baekje (founded in 18 BC) in the northeastern area of modern Seoul. There are several city walls remaining in the area that date from this time. Pungnaptoseong, an earthen wall located southeast Seoul, is widely believed to have been at the main Wiryeseong site. As the Three Kingdoms competed for this strategic region, control passed from Baekje to Goguryeo in the 5th century, and from Goguryeo to Silla in the 6th century.