One of my best activities while barefooting Spain was roaming through old Gothic temples, getting my soles terribly dusty on the unfinished cold floors and walking on the marbled areas. Completely irreligious experience, but it made for a happy pilgrim!
“Do not come any closer,” God said. “Take off your sandals. The place you are standing on is holy ground.” Ex. 3:5 ;-)
Well this is the Alhambra in Granada, for sure not a church ;-) But great to visit though. Especially the Generalife gardens are nice to experience on bare paws! Alhambra - Wikipedia
Please allow me to disagree. For me being barefoot in old churches isn't irreligous at all. It's an important part of my spirituality. Not only being barefoot from time to time, in comfortable places, but living barefoot in everyday life. Feeling the wonders of creation under my bare soles, fresh grass, earth, brooklets, rain, mud... but also share in the burdens of the world with my bare feet. Feeling the rough asphalt in the cities, the dirt, the traces of traffic. And then going barefoot in churches, let my bare feet bring all the impressions from my everyday life, the beautiful as well as the painful. For me that is a special kind of spirituality