Hawk Wargames' Cityscape paper terrain setHere's a peek of it in Alpha Strike action

Ignore the building on the bottom left of the top picture. That one is from a downloadable PDF from Hawk Wargames website that they offer if you want more buildings of a certain type in the set or want to give paper terrain a try, so that particular building is homemade.
Most of the other buildings come from the actual set. Those pieces are from much thicker stock with a varnish finish. If you permanently glue the roof in place, they are sturdier than expected.
I opted to leave them unglued and make cardboard inserts so everything folds flat at the end of the day, but they can sport two or three metal mechs on a roof top during a fight.