Unicorn Gate
The gate swings freely and silently on its hinges. On the other side, the characters see more clearly what they had glimpsed through the gate: a featureless tower wall rises fifteen feet, where a small balcony projects outward overlooking an oval pool in the ground below. There is a border of gravel composed of small, smooth stones of indeterminate color (due to the darkness) that extends about five feet back from all sides of the pool, which is twenty feet across, and of a totally unknown depth. At the back of the balcony, there is of course a doorway into the tower, and this doorway is obscured by a curtain that is slightly billowing slowly, as if recently disturbed.