The exact period of Gwalior Fort's construction is not certain.According to a local legend, the fort was built by a local king named Suraj Sen in 3 CE. He was cured of leprosy, when a sage named Gwalipa offered him the water from a sacred pond, which now lies within the fort. The grateful king constructed a fort, and named it after the sage. The fort covers an area of 3 square kilometres (1.2 sq mi) and rises 11 metres (36 ft). Its rampart is built around the edge of the hill, connected by six bastions or towers. The profile of the fort has an irregular appearance due to the undulating ground beneath.