Cannon Fort sits on a hill behind Cat Ba Town, reached by a steep ten-minute scooter ride or a brisk twenty-minute walk up. The complex consists of two restored gun emplacements with their original cannons, a network of tunnels and bunkers, and a small but well-presented military museum.
The real reason to come is the view. From the upper terrace, Cat Ba Town spreads out below, the harbour beyond, and the karst peaks of Lan Ha Bay march away to the southern horizon. Sunset is the obvious time, with crowds to match; for an emptier visit come mid-morning when the cruise ships have departed. Modest entry fee; allow about an hour to walk the loop.