National Museum of Computing

Back during World War II, giant computers were at work in Bletchley Park to decipher the encrypted messages between Hitler and his generals. Now at the National Museum of Computing you can explore that history through a restored Colossus computer (which lives up in size to its name), and other moments in computing history going back to the 1940s.

The museum opened in Block H in 2007, and includes exhibitions on the process of cracking code, as well as giant mainframe computers, early machines, and the world's oldest working digital computer (the Harwell Dekatron/WITCH). There's also a gallery for hands-on "retrocomputing," in addition to a recently added gallery dedicated to the role of women in computing. You can also view restoration projects in process as the museum continues its dedication to not just collecting, but keeping historic computers in working order.