Vajrasana or the Diamond Throne is the seat of the Buddha’s Enlightenment. Built in the 3rd century B.C. by Emperor Asoka, it is made of red sand stone. Venerable Ashwaghosa in his Buddhacarita reveals that this is the Navel of the Earth. Fa-Hien mentions that all the past Buddhas attained Enlightenment here and the future Buddhas too will attain the enlightenment on this spot.