Birjand Castle is the largest and oldest historical monument in Birjand. It is located on top of the highest western point of hills of Birjand City, and is one of the tourist attractions of Birjand and South Khorasan Province. It covers an area of 3000 square meters and was built in Safavid era. In fact, it is the major core of Birjand City. The castle in Birjand during the Qajar period was completely rebuilt and used.