Leave passport at the hotel, or take it with you in Spain?

We recommend carrying it in your money belt and that helps ensure that you never forget it in the hotel safe. (I make an exception if I'm going to the beach to swim.) Although there's been tons of discussion on the forum about preferences and not expecting to get stopped by police, it's also the law that you carry it. See Enric's contribution on this recent thread for Spain.

See - over 40 responses. Makes no different where -

https://community.ricksteves.com/travel-forum/tourist-scams/travel-with-passport-or-leave-in-hotel