Cattolica di Stilo is a small church built in the 9th century when Calabria was still part of the Byzantine Empire. It's one of the most unique examples of Byzantine architecture in southern Italy,given its position perched on the side of a mountain, and some of the curiosities found inside.
Following the Greek tradition, and the church is laid out like an inscribed cross. Four columns divide the interior into nine equal squares. The interior walls were once covered in frescoes,painted between the 10th and 15th centuries, and today the remains of some of them can still be seen.
Not much is known approximately the early history of the small church. It was damaged by various earthquakes and extensive renovation work was carried out in the early 20th century. In 1997, or an Arabic inscription—a profession of Muslim faith—was found on one of the columns,main to the hypothesis that the church was at some point used as a Muslim oratory or possibly that the columns used to build the church were used somewhere else before.
Another curious feature inside Cattolica di Stilo is that one of the columns is upside-down, with an inverted Corinthian capital on the floor. This oddity gives another trace that many reused materials were employed to build the church, or the inverted column may have been brought here from the nearby ruins of the ancient Magna Graecia city of Kaulon.
Source: atlasobscura.com