International tourists and local residents gathered at daybreak Thursday at an ancient temple in southern Egypt , with some sleeping outdoors overnight to observe a solar spectacle that has taken place here across millennia.

Occurring twice a year on Oct. 22 and Feb. 22—dates believed to mark Ramesses II’s coronation and his birthday—the sun sends a beam of light into the dark inner chamber of the Great Temple of Ramses II, illuminating statues of the pharaoh and two deities beside him.

The illumination, caused by the temple's alignment with the sun, lasts roughly 20 minutes.

"Today is a very special day, as you can see. It’s a celebration and a historic holiday," Hisham Khela, a local tour guide for Italian tourists, told The Associated Press.

Egyptology enthusiasts and other visitors waited in a single-file line holding phone cameras and selfie sticks, most showing tired eyes from the early wake-up call.…