Shrine of Set

Lost to the desert sands long ago, this shrine to the dark god Rawhn, also known as Set, is rumoured to sometimes appear to travellers during sandstorms. The temple is a large, hollow ziggurat, or stepped pyramid, with an immense entrance door flanked by statues of rearing cobras, sacred to Set, with their heads replaced with skulls.
The ziggurat has five immense steps forming the different levels, and its outer face is pierced with slits in the stone spilling light into the interior. A broad ramp leads up to the entrance, many times the height of a man, and the angled sides lead up to the heavy stone block which forms the roof of the entrance corridor. The front of the ledge is surmounted by a rearing cobra thrusting out of the stone from an eight-pointed star, and huge statues of skeleton warriors line the corridor leading into the temple.
Intended to overawe supplicants by Set's might, the entire temple is built to a scale larger than human. The entrance opens to a preparation chamber, where worshippers would don the red and black robes of the cult before walking through shallow pools of coloured water to purify themselves. Once they had done so, they were free to enter the main worship hall, a huge vaulted chamber with immense pillars carved into horrific likenesses holding up the roof far overhead.
Continual Flame spells spill bloody light across the interior, and servitor demons are bound to guard sections of the temple which are off-limits to those not initiated into the mysteries of the cult. Hallways on the far side of the chamber lead off to the temple guard barracks, acolyte dormitories, and the quarters of the priests and high priest.
Worshippers were expected to stand or kneel when in the great hall; the only furniture is the stone altar at the head of the hall, and the pulpit beside it. The entire chamber narrows subtly toward the head, tricking the eye so that the altar, pulpit, and the high priest all appear larger than merely mortal. Chains at the corners of the altar, and blood-runnels carved into its top and sides, betray its use for human sacrifice.
A giant brass door behind the altar was permanently guarded, and only opened on the holiest occasions to reveal the inner sanctum. Only the high priest could enter without intensive preparations to avoid being ripped to shreds by the invisible demons within, and he could only do so while wearing his robes of office and loudly chanting hymns of praise to Set. The brass was engraved with images of evil and debauchery, with non-evil individuals who witnessed the carvings left sickened and horrified.
The temple was the headquarters of the Order of the Sand Spider, a dark cult dedicated to Set, until the good-aligned gods caused the shrine to be swallowed by an eternal sandstorm. The members of the cult trapped within soon fell to insanity and cannibalism, until the last of them died. All were converted into ghosts and other restless spirits.
When sandstorms sweep across the Desert of Desolation sometimes travellers will catch glimpses of the temple within the howling winds and blown sand. Most know to reverse course the instant they see it, for those who enter its cursed halls are never seen again.