Two UNESCO World Heritage Sites in three days, with Hanoi in between. Day one is the capital on foot: the Temple of Literature, Tran Quoc Pagoda on West Lake, Hoan Kiem, the thirty-six guild streets, and an egg coffee somewhere up a staircase.
Day two is the bay — out on the expressway, six hours aboard, Sung Sot Cave, kayaks at Luon Cave and the climb up Ti Top — and back to the same Hanoi hotel. Day three runs south to Ninh Binh for Hoa Lu, two hours on a sampan through the limestone caves at Trang An, and the five hundred steps up Mua Cave, before the airport.