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:Duino Castle was built by the Wallsee family in 1389 on the cliffs overlooking the Gulf of Trieste. It replaced an older castle from the 11th century. Over time, the Wallsee family disappeared and the castle, after having been used as a prison, became the residence of the Luogar and Hofer.
At the end of the 19th century it became the property of Prince Alexander von Thurn und Taxis from the Czech branch of the House of Thurn and Taxis. It remains with the family to this day with his great-grandson Prince Carlo Alessandro della Torre e Tasso, Duke of Castel Duino the current owner. The castle has been opened to the public as a museum and park.