Roman Military Palace
Syria
The Palace of the Dux Ripae was the largest and most important building in Dura-Europos during the period of Roman rule. According to the inscriptions, the Palace was erected under Elagabalus (AD 218–222) and it seems to have survived until the Sassanid conquest of Dura-Europos in AD 256.
Data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).