In Palmdale California, at the corner of 25th St E & E Palmdale Ave [1], there's what is essentially a parking lot with a chain link fence around it. Sitting there are a SR-71, a A-12, a D-21 (supersonic recon drone originally launched from A-12 variant), and a U-2. You can just sit there and take all the pictures you want.

[1] https://www.google.com/maps/@34.6026576,-118.0860601,117m/da...