Bulgaria Cyrillic Skull Crypt

Now I’m not one for superstitions, spells and curses but when we paid a quick visit into this crypt aside a Bulgarian monastery, Nicola & Jonathan all looked at me with discern when I moved a couple of the skulls to take a photo of them in the light. They warned me that I would become cursed, I laughed, but later I was told these were the skulls of monks.