"I dislike bringing people here." The voice of the guide from the tourist office in Malko Tarnovo drops, as we approach the summit of Golyamo Gradishte, the highest peak in the Bulgarian part of the Strandzha mountains. It is summer. The sun shines through the thick foliage of the oak forest. The only thing negative about this pristine location, in the Strandzha Nature Park, are the midges that swarm around our eyes.