Serdica Amphitheatre was part of the ancient Roman city of Ulpia Serdica, now Sofia, the capital of Bulgaria. Discovered in 2004 and the subject of excavations in 2005 and 2006, the ruins of the amphitheatre lie on two adjacent sites in the centre of modern Sofia. The amphitheatre was built in the 3rd–4th century AD on top of a 2nd–3rd century theatre, which had been ravaged by the Goths. However, the amphitheatre remained in use for less than a century and was abandoned by the 5th century.
The Amphitheatre of Serdica was among the biggest in the eastern part of the Roman Empire and the largest in what is today Bulgaria. It lay outside the city walls of Serdica and hosted fights between gladiators and wild beasts, which were advertised at the entrance of the city.
References:Rosenborg Palace was built in the period 1606-34 as Christian IV’s summerhouse just outside the ramparts of Copenhagen. Christian IV was very fond of the palace and often stayed at the castle when he resided in Copenhagen, and it was here that he died in 1648. After his death, the palace passed to his son King Frederik III, who together with his queen, Sophie Amalie, carried out several types of modernisation.
The last king who used the place as a residence was Frederik IV, and around 1720, Rosenborg was abandoned in favor of Frederiksborg Palace.Through the 1700s, considerable art treasures were collected at Rosenborg Castle, among other things items from the estates of deceased royalty and from Christiansborg after the fire there in 1794.
Soon the idea of a museum arose, and that was realised in 1833, which is The Royal Danish Collection’s official year of establishment.