Wow, for real? That is unbelievable. Are you pretty much free to explore or is any of it blocked from the public? I don't even have to see the image and I can picture your photograph of that stone tablet. It's so fascinating to me. I had no idea this existed in Bulgaria.

I'm not a huge cyclist or anything but I've done my fair share of long bike rides. It sounds like Bulgaria would be a great way to explore in this way.