Raga or Rey city(it literally means "the royal city" ) is one of the oldest cities in the world and also one of the most important sites in Iran history. Rashakan Castle located in Rey City is one of the historical monuments of this city. Rashkan Castle is made of stone and mortar and belongs to the Parthian period. The name of this castle is derived from Arshak, the founder of the Parthian Empire. This 2300-year-old castle is a valuable heritage of the Parthians and later the Sassanid Empire.
Rashkan Castle was the spring capital of Parthian kings and was also one of the important sites for the celebration of Nowruz in the Sassanid Empire. Today, this ancient castle attracts several tourists, archeologists, and photographers from all around the world.