The ancient cultural and communication complex “Serdica” is separated into two zones and incorporates sections with varied objectives. The “Largo” zone, located under Nezavisimost Square, combines ancient remnants with a venue for cultural activities. The remnants of one of the Roman town’s two major roadways, the decumanus maximus, which links the city’s eastern and western gates, may be seen here. South of it, a massive residential building encompassing an entire insula (urban block) can be observed.
The structure also housed tiny stores where visitors and residents of the town could buy food and other items. A lapidarium is near to the structure. It exhibits various monuments from the National Archaeological Institute with Museum at the Bulgarian Academy of Sciences, some of which were unearthed from Nezavisimost Square and the surrounding region. The “Largo” zone has three rooms with distinct functions: a special hall for conferences, seminars, and debates, an exhibition hall with a publicly accessible info-point, and a hall for temporary exhibitions and projects. Exhibitions, contemporary and classical concerts, film projects, plays, and other cultural and social activities are also held in the space underneath the domes. The European Researchers’ Night, the yearly Cantus Firmus European Music Festival, and the start of the 2019 Webit.Festival are among the most prominent events hosted there. The “Largo” area is open daily from 7:00 a.m. to 22:00 p.m.
The archaeological display under Knyaginya Maria Luiza Boulevard is located in the complex’s second section. Excavations were conducted out between 2010 and 2012 as part of the rebuilding of Sofia’s downtown areas and the construction of the second Metro line. The complex is made up of multiple insulae that run along the major arteries of the Roman city and housed the city’s wealthy. Parts of six streets are evident over an area of 6000 m2, as are two early Christian basilicas, thermae, and five structures with residential, manufacturing, and trading purposes.
The majority of the structures are substantial in size, have a private heating system and a bath, and are notable for their elaborate interior decorating, all of which demonstrate the wealth of Serdica’s city elite during its heyday (IV – VI century). The Felix mosaic, which is totally conserved in one of the buildings, is one of the complex’s centerpieces. The remains of one of the region’s early Christian temples, the Episcopal basilica of Protogenes, where apparently the Council of Serdica assembled in 343, as well as the home of Archbishop Leontius from the end of the VI century, are significant for the city’s history. Sections of previous structures from the II–III century, as well as representative objects discovered during archaeological digs, as well as intriguing traces of ordinary life in ancient Serdica, are shown in various areas of the complex.