Lennusadam, or the Seaplane Harbour, is a maritime museum located in the Old Town of Tallinn, Estonia. It was opened in April 2012 and is one of the largest maritime museums in Europe. It was built to showcase the history of Estonian maritime culture and to preserve the country's maritime heritage. The museum houses a variety of exhibits related to maritime history and culture, as well as a collection of seaplanes, ships, and other maritime artifacts.

The museum is housed in a former seaplane hangar, which was built in 1916 by the Russian Imperial Navy and is one of the oldest surviving seaplane hangars in the world. The hangar was used for seaplane operations during the First World War and the Estonian War of Independence. Inside the hangar are a variety of exhibits, including a number of historic ships, a submarine, and a variety of seaplanes. The museum also houses a number of interactive exhibits, including an interactive map of the Baltic Sea, a virtual tour of a submarine, and a virtual reality experience of the Battle of the Gulf of Finland.

Visitors can also learn about the history of maritime navigation, shipbuilding, and the development of seaplanes. The museum also has a café, a souvenir shop, and a library. In addition to its permanent exhibits, Lennusadam often hosts special exhibitions and events. These include maritime workshops and lectures, film screenings, and special events related to maritime history and culture. The museum also offers a range of educational programs for children and adults.