Then like Tomb of Horrors, but not nessisirially as deadly? Those can be fun if the groups in the right frame of mind. I took a group through that. Well a group of 4, but one guy did most of the work. The rest were not in the mood to think. So, one guy got 75% of the experince. The other didn't even bother to complain.
They can be fun, but only once in a long while. Maybe every 20 seesions if that often. It's nice to have different challenges but you have to know the group and realize if they can handle it.