Rachovets Fortress stands on a hill outside modern Gorna Oryahovitsa, with traces of Thracian, medieval Bulgarian, and Ottoman-era occupation. The ruins are fragmentary, but the position is the point: the hill controlled approaches toward Tarnovgrad and the routes through this part of north-central Bulgaria.
Go for the landscape and the history rather than intact walls. With good light, the site makes a satisfying short excursion from town, especially if you have already seen Veliko Tarnovo's more dramatic fortifications and want the quieter counterpart.