Beef Gate

Dragondawn
* The right half of the first island isn't supposed to be visited early on. It's possible you'd get ripped apart by crabs if you visit it during Act 1 or 2. (Which can be easily defeated around Level 8.)
* The tower. You're supposed to be around Level 25 and have learned the spells in your headquarters. It's possible to beat the game without those, but you'd have a harder time defeating enemies starting with this dungeon.
* Some enemies in World 2 could easily defeat the party unless you equipped them with Anti-Magic items.