Allahabad Fort was built by Emperor Akbar in 1583 AD. The massive fort stands on the banks of the river Yamuna near the confluence with river Ganges. Praised for it's architectural design, the Allahabad Fort is the largest fort constructed by Akbar. This fort has three magnificent galleries which are flanked by high towers. At present, the fort is used by the army and visitors have limited access to the area. The outer walls of the Allahabad Fort rises above the level of water.Saraswati Koop is one of the most popular attractions located within the fort. It is said to be the source of the river Saraswati.. The Patalpuri temple and Akshaya Vat or immortal Banyan tree are also located inside the fort. In addition, the fort also has Ashoka Pillar which was built back in 232 B.C by Mauryan Empire. This gigantic pillar is a polished sandstone with an height of 10.6 metre. Visitors require a permit from the Ordnance Depot or the Tourist Office for visiting this Fort.