This is a ruin pack for the Ruins Mod (Time fork) https://mods.factorio.com/mod/AbandonedRuins_updated_fork, it comes with a scenario where there is a settlement at the crash site the houses here are empty but can be mined for loot.
There are 16 small ruins, 68 medium ruins and 28 large ruins. Each house will contain some loot and can also be mined for additional resources, be carefull when mining them you may disturb the biters inside!
This mod will also load the base ruins and the Fortress ruins if they are installed and active, just select OldAbandonedRuins in the mod settings as the default ruin pack.