Try this sign pointing to Mecca https://thesearchforbeauty.files.wordpress.com/2012/03/img_0...

I wonder if it actually points at Mecca…

It points to the town of Mecca which is close to the Salton Sea in Southern California.

Looks to be in Kentucky. Has both a Paris and a London, only 90 miles apart, so it's easy enough to pick a point on highway 64 that would be nearer to Paris either coming from Louisville or Huntington. Impossible to know which direction though without more context.

As a non-American, can someone explain why there are US cities with the exact same names as cities in Europe, Egypt, Greece, etc.?

Because settlers from Europe came to America and didn't give af what the Indians called their land. So they named places after ones they knew; New York, New England, Boston.

Toronto, Ontario, Niagara, Ottawa, Canada, Mississauga.

Canada kept a few.

I guess mississippi is one but most US places have white names.

Hamilton?

Heading west from Clappison's corners near Waterdown.

Specifically: https://goo.gl/maps/LidB2yoxMP9pjpXJ7

Lol look at that, a London and Paris right next to each other in Ontario too... nicely done.

in the US, based on the sign style and the road striping, and the drainage grate

On the side of the 403.

somewhere near Versailles, KY ;)