Tam Coc — "three caves" in Vietnamese — is the postcard image of Ninh Binh: a slow rowing boat trip on the Ngo Dong River between vertical limestone peaks rising from flooded rice paddies, passing through three natural cave tunnels. It is beautiful, and deservedly famous.
The boats are narrow sampans, rowed by local women (and occasionally men), often using an unusual foot-rowing technique to free their hands. The rice paddies on either side of the river turn golden in autumn (October–November), which is the peak season for scenery.
Tam Coc is heavily touristed — the main approach road is lined with bicycle hire shops and souvenir stalls — but the boat trip itself remains worthwhile. Arrive before 8am for the best light and smallest crowds. Souvenir sellers in small boats may approach mid-trip; saying no firmly is sufficient.