The NSA Museum

Just outside the heavily fortified campus of the National Security Agency in Annapolis Junction, Maryland, sits a museum highlighting the work of that agency's employees. But how much is the mysterious intelligence outfit willing to reveal? Plenty. From original Enigma machines to an exhibit on the Soviet attempt to steal the Manhattan Project's secrets to a replica "cypher wheel" designed by Thomas Jefferson, the National Cryptologic Museum offers a surprisingly meaty assortment of cryptography artifacts.

The run-down building is even looking to grow. A sign announces that an exhibit on "information assurance" will open soon, and an ongoing capital campaign will eventually result in a new (and largely privately funded) 87,000-square-foot home for the museum.

There's no mention of the domestic spying efforts brought to light by Edward Snowden. But perhaps decades hence he'll be recognized there alongside other fallen heroes and living honorees.