Caravanserais were a common feature not only along the Silk Road, but also along the Achaemenid Empire's Royal Road, a ancient highway that stretched from Sardis to Susa according to Herodotus: "Now the true account of the road in question is the following: Royal stations exist along its whole length, and excellent caravanserais; and throughout, it traverses an inhabited tract, and is free from danger." Other significant urban caravanserais were built along the Grand Trunk Road in the Indian subcontinent, especially in the region of Mughal Delhi and Bengal Subah.