While temples themselves tend to be fairly simple, they’re typically situated in a small compound with multiple buildings. These may feature…

• Gated walls with separate entrances for men, women, and clerics
• Gathering courtyard(s)
• Facilities for ritual bathing/washing and/or care for the sick and elderly
• Storage chambers for sacrifices, gifts, and supplies (wood, oil, wine, etc.)
• Living quarters for clergy and possibly monks
• A well
• Altar (outdoors, for burnt sacrifices; indoors or outdoors for blood sacrifices)

A subterranean temple would likely include the extra facilities within it, and have the temple itself at the center. Above or below ground, a temple typically features…

• Entrance/portico at the top of stairs, suitable for announcements
• Antechamber with statues and murals
• Sanctuary hall with altar, statues, murals (no benches but perhaps rugs for kneeling)
• Clergy chambers (preparation, storage of ritual items, etc.)
• Inner sanctum (holy of holies, oracle room, etc.), usually with a huge statue
• Treasure vault (for storing gold and silver furnishings, donations, etc.)
• Underground cellar for storing food and other supplies
• Underground crypt/ossuary, possibly quite extensive