Shoppers gather at the main entrance of Souk al-Melh (Salt Market) in the old eastern section of the city of Sana’a, capital of the Republic of Yemen. The eastern portion of the city houses large souks (markets), each devoted to a certain product. Located about 145 km (about 90 mi) northeast of the port of Al Ḩudaydah on the Red Sea, Sana’a serves as an important trading center for the nation. An ancient city, it first became an important center in the 4th century ad, and it retains much of its unique architecture.