Nah it's a real house. Forget who placed it somewhat recently. Apparently over 5 years nobody tried to place a house inside of the orc cave and it was a valid location
Thats the orc fort... a while back erlkonig was the first player on the shard to actually try place a house there (some 5 years after launch) but out of respect to what he believed was wrong he took the house down after making a thread about it and we all giggled at the house placement.
Seen staff not allow some houses (on roads or in graveyards), sometimes it's a if falls then no replace (house in stable yard at serps). Be really sweet house to have, think of the money you could make over time
go to the Compassion Desert entrance head back and to the right, go through the ore cart tunnel and keep to the right