Entrance to the Mehrangarh Fort, Jodhpur This view of the entrance road is taken from inside the fort, looking back towards the Loha Pol (Iron Gate) in the distance. Stone fortifications were originally introduced to India by the Mughal invaders. The forts typically lack keeps (Tughlukabad is an exception) and domes (domes are vulnerable and serve no practical function; you can't put anything on top of them, or do anything with them).