Best surface for tires to sit on for extended periods?

By no means am I jacking the tires off the ground. With three axles under there, I can guarantee that I'll never want to hook up and go again for sake of all the work it would take to leave. We take the trailer out a few times a year but considering how long on average RV/trailers sit between movements, the thought just crossed my mind that maybe the surface the tires are sitting on could help. Thanks everyone.