Allahabad is a city in Uttar Pradesh state, north India. Triveni Sangam, the juncture of the Ganges, Yamuna and "imperceptible" Saraswati waterways, is viewed as heavenly by Hindus. It's close to the sixteenth century Allahabad Fort, worked by Mughal Emperor Akbar. In the fortress are the old sandstone Ashoka Pillar, the underground Patalpuri Temple, and a consecrated banyan tree.