The Cité de la Mer is an ocean-themed museum located in Cherbourg, France. It showcases the history of underwater exploration and maritime activities. Visitors can explore exhibits on submarines, marine life, and the Titanic, as the museum is situated near the harbor where the ill-fated ship was supposed to dock. One of the main attractions is the Redoutable, a decommissioned French submarine. Guests can take guided tours to learn about its history and technology. The museum also features an aquarium, offering a glimpse into the diverse ecosystems of the sea, making it a popular destination for families and marine enthusiasts.