A pair of towering doors 60 feet high rests in the rock of the Southern Mountains, framed by a row of cyclopean pillars. A keyhole sits in the portal at chest height, but the lock won't open by any means other than the golden key described in 'A Realm Reborn: The Key to a New Kingdom' (found in the Mysterious Pyramid).
The book claims a mighty citadel where sorcerers and djinn walked the streets lies beyond The Doors, but nobody in The desert has passed through the silent gateway in a thousand years.