Felix Romuliana was an imperial palace built on the orders of Galerius Maximianus on the spacious plateau of Gamzigrad, near the city of Zaječar. Galerius, who was born in this area, raised the palace in the 3rd and 4th centuries in honour of himself and his mother Romula, after whom he named it. It belongs to a special category of Roman court architecture associated only with the period of the Tetrarchy and is the best-preserved example of this style.
The palace is surrounded by imposing walls which protected the town itself from barbarian attacks. The remains have been discovered of both an older and a more recent fortification, built over a period of some ten years. The thoroughfare which connected the east to the west gate divides the area within the walls into two parts of differing function. The northern half includes the imperial palace complex, with its small temple and monumental altar. In the southern half are buildings for public use (a large temple with two crypts on a rectangular floor-plan and public baths) and buildings used to service the palace (a horeum and a single-nave structure with portico). The structures are richly decorated with frescoes, stucco and floor mosaics depicting figures and geometric motifs.
Since 2007, the archeological site Felix Romuliana has been listed on the UNESCO World Cultural Heritage List.