Tam Coc or "Three caves" is 120 km (75 miles) south of Ha Noi. A two-hour boat journey  is delightful. Along the scenic journey, you will see the Thai Vi Temple where King Tran Nhan Tong (1279-1293) spent the end of his life as a monk. Mountains of unusual shapes loom overhead. At the end , the boat passes 3 caves: Hang Ca, Hang Hai, Hang Ba.