Nisa (also known in antiquity as Parthaunisa) was an ancient city, located in the vicinity of the modern village of Bagir, 18 km from Ashgabat in Turkmenistan. Nisa was described by some ancient authors as one of the earliest capitals of Parthians. Traditionally, it would have been founded by Ársaces I (reigned from 250 to 211 BCE), and would be the royal necropolis of the Parthian kings, although it was not possible to discover until today if the fortress discovered on the site was a residence or a mausoleum. Excavations at Nisa revealed several important buildings, mausoleums and shrines, various documents with inscriptions, and a treasure that had already been looted. Several Hellenistic works of art were discovered, as well as many ivory rythms, coins decorated with Iranian themes or classic mythological scenes. Nisa was later renamed Mitradacerta (Mithradatkirt, "fortress of Mithridates"), by Mithridates I of Parthia (171-138 BC). The city was totally destroyed by an earthquake in the first decade BC The fortress of Nisa was declared a World Heritage Site by UNESCO in 2007.