Sa Dec (Khmer: ផ្សារ ដែក / Phsar Dek, Chinese: 沙的) is a provincial city in Đồng Tháp Province (Sa Đéc and Kiến Phong) in the Mekong Delta of southern Vietnam. It is a river port and agricultural and industrial trading center, The Sa Dec economic zone consists of Chau Thanh, Lai Vung and Lap Vo districts. During the Vietnam War in 1966 and 1967, it was the site of Sa Đéc Base, an American PBR (Patrol Boat, River) base. Later on, it became a Swift Boat base, as well. Before the nineteenth century, it was the capital of Dong Khau Dao, and it was known as one of the largest cities in the Mekong Delta.