1. It's Permanent. I tried it myself. It's quite interesting, that map. Also, it gives you two little quests, for the quest maniacs.
2. One of those quests gives you random rewards! Mainly, MV's hat, for your main stat (+7, apparently), and 200 hp. They last 3 months apparently. Didn't get one yet, but some guy said his expired in JUNE. Also, got a heartstopper from a drop from in there, and I've heard someone say the stuff in there has a VERY low chance to drop a gelt
EDIT: Managed to get my hands on a DEX hat. The stats are 7 DEX, 200 hp, no slots.
They last 1 month, not 3
2. One of those quests gives you random rewards! Mainly, MV's hat, for your main stat (+7, apparently), and 200 hp. They last 3 months apparently. Didn't get one yet, but some guy said his expired in JUNE. Also, got a heartstopper from a drop from in there, and I've heard someone say the stuff in there has a VERY low chance to drop a gelt
EDIT: Managed to get my hands on a DEX hat. The stats are 7 DEX, 200 hp, no slots.
They last 1 month, not 3