Hoa Lu is some 110km or 2.5 hours bus from Hanoi. Located near the Ninh Binh city, Hoa Lu is the site of a 10th-century capital of an ancient Vietnamese Kingdom called Dai Co Viet. This small Kingdom covered an area of only 300 hectares, and reigned from the 10th century, during the Dinh and Le dynasties, to the 11th century, during the Ly Dynasty. The Kingdom was enclosed by a citadel. The citadel and the Yen Ngua limestone hills provided good defence for this kingdom against the invaders.
Not much of this ancient kingdom is left standing. There are two 17th century temples, modelled after their 11th-century originals that are on most itineraries to Hoa Lu. They are the Dinh Tien Hoang Temple (King Dinh temple) and Le Hoan Temple (King Le Temple).