Sims 4 Ancient Ruins Problem

I sent my sims to the ancient ruins for a party and all the furniture and stuff in the ancient ruins was gone except the ancient walls and I thought I could fix it by editing but it says I can't edit that lot only the lot behind it and I tried to look for the ancient ruins lot in my gallery to see if I could just place down a new one but it looks like I can't. Does anyone know if there's any way I can get the original ancient ruins lot back?