The Haunted Dimensions site has paper models of three small crypts. The only downside of these is that the back of the crypts are defaced with site advertising. Still, there’s also a brick wall there that you can paste the crypts up against.
paper model
Paper Model “L” Tracks
In N scale here are some free paper models of the tracks of Chicago’s famous “L”.
Paper Testudo Model
For Warhammer Ancient Battles, here is a paper model of a Roman testudo in 25mm/28mm scale.
Paper Model of An Elf Tower
I’m not at all sure what scale this free paper model of an elf tower is in. Its either a big 15mm or a small 25mm scale. In either case, it would be a nice addition to the table for a fantasy game.
Half Timbered Town Houses
Here’s a site with four very nice paper models of 25mm / 28mm half-timbered houses that would be appropriate for a fantasy or medieval town setting. There are “shoddy shops” a “posh place,” a plain half timbered house and a building that is more fantasy oriented. All are in pdf format.