It is the Chapel of Bones, or Capela dos Ossos, in the Portuguese city of Évora.
I have posted about it both in color and in b&w :)
https://peakd.com/hive-102880/@fotostef/would-you-visit-this-chapel
https://peakd.com/adsactly/@fotostef/we-bones-here-for-yours-await
Tres cool. I've been to one In poland before... that was pretty cool!