From news.bg:

Ruins of a little late-Roman fortress, part of the defense system of the Romans in nowadays Northern Bulgaria, archaeologists have found by excavations in Svalenik village.

The fortress was raised in IV Century as a watch fortification, controlling the road in the River Valley of Malki Lom River.

For now archaeologist revealed the south wall and two inner rooms of the fortress.

The finds- coins and pottery- give a reason to claim the fortress had survived after the big Huns and Goths invasions in the V century, but as an already fortified settlement of agriculture population.

Some objects, especially ceramic pottery and arrow gads shows life here proceeded through the period of Second Bulgarian kingdom.


... I don't think the photo accompanying the original article is the actual fortress for some reason ...