Tyler L.
Google
This is a really stunning place to visit and an absolute must if you are in Elche.
The architecture is insane, definitely one of the most beautiful buildings I've ever been in.
You can go inside, but it's through a little hole in the wall to the left of the grand door, it isn't obvious at all and I can't remember seeing a sign. You can go inside for free, but you have to play to climb the tower.
I didn't climb so not sure the cost