The Rock-Hewn Churches of Ivanovo are a UNESCO-listed group of medieval chapels, cells, and monasteries cut into the cliffs of the Rusenski Lom valley. Their best-known frescoes survive in cave interiors, where the rough rock setting makes the painted saints feel unusually immediate.
They are outside Ruse, but close enough to work as a focused half-day trip. Wear practical shoes for paths and steps, and allow time for the landscape as well as the art; the cliff setting is central to why the site matters.