The Obelisk Quest
Go to Murmurwoods and wait until June 24. Between 5 a.m. and 9 a.m. look for the Unicorn King. Take the key from him and return to Ravenshore. Then, find the fenced in area.
That you must have gone and collected all the Obelisk information first before going to Murmur Woods or the Unicorn King will not be there.
Good Unique Hidden Locations
If you see a tree or rock in the game that says "tree" or "rock" you will get unlimited potion bottles (there is one on the main island of regna and dagger wound. Hint: dump everything in your inventory before clicking on the tree or
WARNING: Save before you do this - once my brother lost ALL his spells from his Lich.