You can tour the interior of a decommissioned Kilo-class submarine, which is very immersive. The interior space is cramped, but the pipelines, crew quarters, and engine room have been preserved in their original state, providing a direct understanding of the working and living environment of the submarine crew. The exterior is great for taking photos, especially with the bay view. The downsides are the narrow entrance, queues, and the stuffy interior; it's best suited for those interested in military and defense history.