Kos Minars or Mile pillars used to be the mile stones on the Mughal Highways or trade routes which inter-connected the Mughal Empire . They were first made by Sher Shah Suri to mark the distance. A kos measures 2 miles of distance. The distance between two Kos Minars was approximately 4 miles. They were more than 30 feet high round pillars of masonry. The design might have varied slightly but their function was the same. They were later on instrumental in day to day governance of the Mughal Empire as they had horses and riders and drummers stationed there for relying royal messages at speed. They also developed as travelers hubs as step-wells & ‘sarais’ were built nearby. The routes on which these Kos Minars were built had been there for ages. Consequently they are near famous battlefields and monuments and ancient cities. Also modern highways have taken place of the ancient tracks used by Mughal horsemen. They were mostly built during 1556-1707 AD. According to a report of the ASI, there are 49 Kos Minars in Haryana, of which 17 are situated in Faridabad district, 7 in Sonepat, 5 in Panipat, 10 in Karnal, 9 in Kurukshetra/Ambala, and 1 in Rohtak district. And all of them, except the one at Rohtak, exist on the Delhi-Ambala and Delhi-Agra highways (NH1 and NH2).