This unprepossessing industrial town 59 miles (95km) south of Hanoi yields few hints of the scenic and cultural wonders hidden in its hinterland, but does provide a convenient base. Often dubbed “Halong Bay on land”, Tam Coc is the area’s real highlight: a tract of spectacular karst mountains rising vertically from carpets of lush green rice paddy.

As with the Perfume Pagoda, metal sampans rowed by women are used to ferry visitors around the sights, which include a succession of low-roofed grottos, temples and pretty stilt villages. During season, a large fleet of boats may be on the water at any one time, which is why we recommend visits to other less well-known beauty spots such as nearby Trang An, where the scenery is no less awesome but crowds considerably lighter. Also worth a detour are the ruins of Emperor Tien Hoang De’s imperial capital at Hoa Lu, where jungle-draped limestone hills serve as a backdrop for ancient citadels, temples and impressive fortifications.