Temple

An altar with a priest in the same room is a temple. If the priest and altar are co-aligned with you, the temple is a sanctuary.

Known locations of temples
Minetown is guaranteed to have a temple altar.

The room in Moloch's Sanctum housing the high priest of Moloch is also a temple.

The Valley of the Dead contains a temple of Moloch with an unaligned altar.

What to do in a temple
You can donate gold to the priest to get extra AC. For more information, see protection.

It is possible to change the alignment of an altar in a temple by sacrificing a unicorn, but doing so will anger the priest. More information is on the page about altars.

What not to do in a temple
When you are BUC testing rings, do not put them on inside the temple. If the ring is a ring of conflict, chances are you will have YASD on your hands.