This review is of Bulgaria's Dzhendema Reserve, which I hiked through without initially realizing that I would be in an UNESCO World Heritage Site. 

My actual hiking goal was Bulgaria's tallest waterfall, Raysko Praskalo, which is located in Central Balkan National Park.  Approximately 1.5 hours after starting the hike, I encountered a sign informing that I was entering an UNESCO World Heritage Site, which puzzled me as I had no idea that I was even in the vicinity of one.  The mountain forest provided a very pleasant hike, but I would not have known about is specialness but for the sign.  I believed that I hiked for about an hour in the forest before another sign informed me that I was exiting the UNESCO World Heritage Site. 

After another 15 minutes of hiking, I arrived at Rai Hut, where lodging and hearty food are available.  The mountain waterfall is just beyond the Hut, and I thought the waterfall - which is not part of the UNESCO World Heritage Site - was worth the hike that required moderate to medium exertion.  I am not sure if the actual UNESCO World Heritage forest alone would have been worth the hike, but the forest did contribute to the joyfulness of the hike, so I certainly am not going to complain (Well, I could perhaps complain, as I had a nasty trip while I was in this UNESCO World Heritage Site, which resulted in a permanent 8 cm-long scar on my shin).

The return (in and out) hike to the waterfall took me a bit less than 6 hours, which also included me taking plenty of time to take photos. 

With respect to getting to the trailhead, my lodging host drove me to it from the peaceful town of Kalofer.  The drive took us about 10 minutes.  After the hike, I walked back to Kalofer, and the same distance took me about an hour.  It is not a walk that I would recommend while a good strip of your skin is gone from your shin.

Note that Central Balkan National Park is part of the tentative list of Bulgaria.