Nalrajar Garh fortification wall ruins dating back to 5th-century CE. are probably the only standing fortification ruins from Gupta period which are located in a dense jungle in North Bengal near Indo-Bhutan border. A prominent feature of its fortification walls are two parabolic arches. Many fortified cities like Nalrajar Garh, Bhitagarh had risen in Northeastern India owing to trade activities with southeastern China.
