Ключевые слова: ancient, arch, architecture, bridge, bulgaria, cliff, europe, forest, green, hill, landmark, landscape, mountain, mountains, national, natural, nature, old, outdoor, park, phenomena, pine, rhodopi, river, rock, rocky, scenery, sky, stone, stream, summer, tourism, tourist, travel, treasure, tree, trees, tunnel, view, visit, wander, water, wonder, wonder bridges,