Suraj Pal's descendent, Anangpal, often described as the founder of Delhi, built the citadel of Lal Kot, some 10 kilometres from Suraj Kund. The kingdom of Delhi was captured by the Chauhan Rajputs in the 12th century. Prithviraj III built massive ramparts around the area and called it Quila Rai Pithora. They were later demolished by the slave kings and Lal Kot became the site of the first mosque in India - Quwwat-ul-Islam Masjid.Archaeological excavations uncovered the earliest of proper settlements in Delhi.Only ramparts of the city remain now — date back to the 11th century, when Tomars ruled the city.Lal Kot once used to be a grand fort built by Anang Pal Tomar.Heavy encroachment by population is endangering the historic saga of the site.