You can get close enough to touch (but you mustn’t touch) the SR71 at the Udvar-Hazy center of the Smithsonian!
https://www.sacmuseum.org/what-to-see/aircraft/sr-71a-blackb...
[1] https://www.google.com/maps/@34.6026576,-118.0860601,117m/da...
Was it rough or smooth? It looked smooth but I wonder if it felt rough!