A lot of ye are saying Last Cave, and I must agree. I always found it pleasantly unsettlin' though, if that makes sense. The cold dankness made it so eerie and uncomfortable, but also safe and oddly nostalgic for some reas'n.
Anyway, I always found the bar that used to be on the side of the forum displayin' all the different maps and their user counts unsettlin'. Made me feel... distant. Wary.