Nisa was the capital of the Parthian Empire, which dominated this region of central Asia from the mid 3rd century BCE to the early 3rd century CE. Criterion (iii): The Parthian Empire was one of the most powerful and influential civilizations of the ancient world, and a brilliant rival of Rome which prevented the expansion of the Roman Empire to the east. Nisa, the capital of the Parthian Empire, is the outstanding symbol of the significance of this imperial power. The two tells do not in any sense represent the original appearance of the Parthian capital, but their present appearance is due solely to natural erosion. Nisa is also one of the eight State Historical and Cultural Parks (SHCP) that have been created to protect the most significant sites in Turkmenistan.