Mirjan Fort is located on the west coast of the Uttara Kannada district in Karnataka. The fort known for its architectural elegance was the location of several battles in the past. It is about 0.5 kilometres (0.31 mi) from the National Highway 17 and 11 kilometres (6.8 mi) from Gokarna, the famous Hindu pilgrimage centre on the west coast of India.
According to the first historical version, Queen Chennabhairadevi of Gersoppa (under the Vijayanagara Empire) was initially credited with building the Mirjan Fort in the 16th century. She ruled for 54 years and also lived in the fort. During her reign, the port at Mirjan, which is 32 kilometres (20 mi) to the south east of Karwar, was used for shipping pepper, saltpetre and betel nut to Surat. Gersoppa, a district annexed to Bednur, was famous for the pepper exported from this region. Consequently, the Portuguese gave the epithet "Rani, the Pepper queen" to the Queen of Gersoppa.
The fort is built over an area of about 4.1 hectares (10 acres). It is built with laterite stones. It was built with high walls and bastions. The fort has four entrances (one main and three subsidiary entrances) and many wells, which are interlinked and with access channels leading to the circular moat (used as a defence measure to protect the fort) that once fully surrounded the fort, and leading to the canal works outside the fort's limits. At each entrance, there are wide steps to enter the fort. The fort is double-walled and has high turrets on the bastions. It is now seen mostly in ruins but is being restored by ASI to some extent. The ruins have been inferred as remnants of a secret passage, entry doors, a darbar hall and a market place. Stone images of Hindu gods and goddesses are also seen under a large tree.