Every Sunday morning, between 10 a.m. and 12.30 p.m., the entry in Porto Military Museum is free. In this museum, you will be able to visit many rooms of expositions that are dedicated to miniatures, uniforms, small arms and heavy artillery pieces. There are also some rooms that are dedicated to political and military events that took place in Porto. Porto Military Museum can also be visited in the other days of the week. You can check the opening hours here.