At Sploid, Jesus Diaz shares some photos from the secret assembly line that built the SR-71 aircraft:
Built and designed in the 1960s after the A-12 Oxcart, the SR-71 Blackbird is still the fastest, most vanguardist air-breathing airplane in the history of aviation. These once classified photos reveal how Lockheed built both birds in secret, in California. They look taken at the Rebel base in Hoth.

The Blackbirds kept flying long after their retirement from the USAF. One of them stayed at NASA: Here’s a photo from the Armstrong Flight Research Center (then Dryden) of an SR-71 being retrofitted for test of the Linear Aerospike SR Experiment (LASRE).
H/T to Dave Owens for the link, and also a H/T to Jeff for linking to another photo story about how the aircraft were transported from Lockheed’s Skunk Works to Area 51.