In November 2012 I have visited the Rock Churches of Ivanovo and for me was a very nice day. A couple of friends and I traveled by car from Bucharest (Romania) to Ruse (Bulgaria) and then to the UNESCO site which is only 20 km away from Ruse. First you should know that you have to climb some stairs, some big stone stairs but do not worry it is not so hard. The churches were made in stone on the canyon created by the river Rusenski Lom. There are many cave that were inhabited by the monks, some said even 300, but only a few have the famous paintings. The frescoes dates from 13th and 14th centuries and now are preserved in only 5 UNESCO ones. The only one open to visit is St. Archangel Michael Chapel ("The Buried Church"). It is a small place and there is no guide or book or something but you have to pay an entrance fee… those should be the minor things just because the place is gorgeous and fragile. I didn’t like that they do not interdict the using of the flash of the cameras because you know that those painting are sensitive to light. You should go there even by bike :D