Last updated: 1 August 2026

Quick Summary: What is Cannon Fort, and can you visit? Cannon Fort, also called Entrenched Fortification 177, is a hilltop military relic 177 metres above Cat Ba town, with two large anti-sea cannons, trenches, tunnels and a bomb-proof bunker. It is not currently open to visitors. Vietnamese tourism listings describe the site as having stopped receiving guests, and no official ticket is on sale. Treat it as a landmark you read about rather than a stop you plan around.