Saqqara — the Apis bull catacombs.

A rock-cut gallery holding twenty-four granite sarcophagi, each around 70 tonnes, made for the mummified Apis bulls worshipped as the living form of Ptah. The boxes are precisely squared and polished inside and out, and manoeuvred into side chambers that barely clear them. Mariette found the complex in 1850 by following a single sphinx head still showing above the sand.