Golden Lake

The Golden Lake is hidden inside of Minerva's Door which can only be opened using the Promised Pen. It is located on the third layer of Goldy Pond.

According to Lucas, the water in the lake appears to be abnormal, as the person touching it cannot get wet by it. In the middle of the lake is a floating island with a cabin on top. In the cabin, there is an old elevator and an old telephone. It is revealed that the elevator once led to the Human World, but has since been deactivated. The elevator can only be accessed by using the Promised Pen. The book, Adventures of Ugo hints at how to find the pen cap for the Promised Pen. During a pre-recorded phone call from Minerva inside the floating cabin which contains the elevator at Goldy Pond, he told the escapees that he left "the rest of the details" in "Marvine's bed". In the book, Marvine sleeps inside of a desk drawer, alluding that the pen cap was hidden in a nearby desk drawer.

The golden water seems to also be related to a temple that is important to the seven walls, and Emma's ability to enact a new promise with, although exactly how is currently unclear.