Formed over millions of years, Trang An is an amazing region of karst cones and towers, interconnected by a network of depressions and subterranean waterways, which uniquely have been invaded by the sea in geological-times past. Though it’s possible to walk or bike through much of this amazing landscape, the best to experience it is on a boat tour. Lasting about two hours, a ride on a traditional flat-bottomed boat brings you through the waterways that run between these mountains, and into the caves and tunnels that connect them for a truly unforgettable experience.