Gothic architecture was revolutionary in the 12th century because it allowed for very tall structures with relatively thin walls. And thin walls meant plenty of windows and lots of light. Compared to previous styles, Gothic architecture was light and airy but to inhabitants of the 21st century, these places are dark.
And the darkness makes this photo what it is, since the main lighting is the soft light reflecting up into the faces of the two men attending to the votive candles. In the medieval mindset, light warded off evil, so even a single candle made a dark place safer and more holy.
Canon 5D 1/60s f/1.2 ISO500 50mm