A well-restored fort of the 18th century that holds two one-room exhibitions about arms and Che Guevara. Every evening there is a cannon ceremony where they fire over the Havana harbour. To get there take any bus (ex. from the Parque the la Fraternidad) that crosses the tunnel and get off right after it. Walk about 600 m to the entrance. On your way you can also stop at the smaller Castillo de los Tres Santos Reyes Magnis del Morro located right next to the tunnel.