Sacred Locked Door

In the Trade Cathedral every door is without a lock, for every person is always welcomed in the holy halls of trade.
However, behind the central altar there is a small chamber. In this chamber, apparently older then the rest of the building, there is a door. This has been locked for as long as the building stands.
Many magicians can attest to a strong magical energy emmanating from this door. Mysteriously, the door is on the outside wall of the Cathedral. There are no signs of the door from outside.

Type

Room, Common, Antechamber