Outside the Duane Library (Math/Physics) are photos of the University of Colorado from its beginnings. The first building was Old Main, which I suppose did not have that name then. I got a strange feeling looking at these photos, as Boulder as I know it did not exist then, at the end of the 19th Century. Pretty much nothing was there except for Old Main surrounded by some dirt roads. I remember, about ten years ago now, how at Swarthmore some construction was being done around Trotter Hall. The roads were changed so people could no longer drive their cars through campus. Once something is gone, it takes some mental effort to recall what it looked like before, especially if you’re standing right there in the face of the new orientation. Surely the old photos of CU are on-line somewhere, but I could not find them. On a related note, Google maps is rather nifty, as they have arial photos and maps based on them.