Described as an inland Ha Long Bay, this sublime area west of the town of Ninh Binh, about 60 miles south of Hanoi, was granted UNESCO World Heritage status in 2014 on account of its “spectacular landscape of limestone karst peaks permeated with valleys, some of which are submerged, and surrounded by steep, almost vertical cliffs.” While the description is accurate, it doesn’t adequately capture the experience of a visit. Boats tackle the waters of the Red River Delta, passing hulking karst mountains and stopping at grottoes along the way. Also popular are the boat trips that depart from Tam Coc, south of Ninh Binh, and wind up a twisting river flanked by limestone peaks and verdant fields.