Bishop's Basilica of Philippopolis

The largest late antique early-Christian church discovered in Bulgaria, built in the mid-4th century in ancient Philippopolis (modern Plovdiv). Measuring 86.3 m long and 38.5 m wide, it featured a central nave with two side aisles separated by colonnades of 13 bays, an apse, narthex, and colonnaded atrium. Its floors preserve two layers of polychrome mosaics exceeding 2,000 sq m: 4th-century geometric patterns and 5th-century designs featuring over 100 bird species. The basilica served as the heart of Plovdiv's Christian life until its destruction, likely by earthquake. Remains were discovered during underpass construction in the 1980s and are now preserved in a purpose-built museum opened in 2021.