Warning: time traveling can have unintended consequences. Like the sudden appearance of tacos in unexpected places. Like, say, Ancient Egypt.
It started with a single taco cart in 30th century BC. The pharaohs were baffled by the strange, crunchy, cheesy food. But it spread, and soon the Great Pyramid was a Taco Bell.
The pyramids themselves began to take on a... let's say, taco shape. The Sphinx, in particular, was reimagined as a giant taco shell, with a cryptic message inscribed upon its forehead: "Tacos are the answer."
Read more about the Taco-Pyramid of the Damned