The Vault known as the Midnight Mountains is one of the largest in Orv—the lowest level of the Darklands—and acts as a crossroads for much of Orvian traffic due to its central location. It has the Crystal Womb and Land of Black Blood to the north, Ilvarandin to the west, and the Black Desert to the south.
The Midnight Mountains are at the bottom of the Endless Gulf, which stretches up all the way to Nar-Voth. Moisture seeps down from Lake Nirthran above in Sekamina, and can fall to the Vault floor as rain. This water makes its way into Ilvarandin as what becomes known as the Irikusk River and then flows into the Sightless Sea.
The mountains which give the Vault its name are two miles high on average, but the ceiling is a further two miles above the tallest peak.
The Vault is lit by six glowing "moons", that are actually particularly large mu spores. The intellect devourers of Ilvarandin use the spores given off by these creatures as one of the ingredients for the drug known as midnight milk.
The Vault's central location makes it one of Orv's most well-travelled regions. However, travellers must contend with the dangers posed by denizens of the Midnight Mountains—gugs, troglodytes, mongrelmen, morlocks, driders, seugathis, pech, ropers, and umbral dragons.
- Robert Brookes, Eleanor Ferron, Michelle Jones, Alex Riggs, and Nicholas Wasko. (2017). Heroes of the Darklands, p. 23. Paizo Inc. ISBN 978-1-60125-936-3
- James Jacobs and Greg A. Vaughan. (2008). Into the Darklands, p. 46. Paizo Publishing, LLC. ISBN 978-1-60125-140-4
- Tim Hitchcock, Brandon Hodge, Michael Kortes, Jason Nelson, Russ Taylor. (2011). Lost Cities of Golarion, p. 6. Paizo Publishing, LLC. ISBN 978-1-60125-272-2
- James Jacobs and Greg A. Vaughan. (2008). Into the Darklands, p. 52. Paizo Publishing, LLC. ISBN 978-1-60125-140-4
- Tim Hitchcock, Brandon Hodge, Michael Kortes, Jason Nelson, Russ Taylor. (2011). Lost Cities of Golarion, p. 11. Paizo Publishing, LLC. ISBN 978-1-60125-272-2