Chozagangam Lake now known as Ponneri Lake was an artificial lake that was built by Rajendra Chola I during his reign, it is one of the largest ancient man-made lake in India.
The Cholas possessed a fleet of ships that were able to capture and defend against any attack. It was one of the most advanced marine defence systems of that time.
The Chola empire treated females with equal opportunity as males as many females held important positions such as bodyguards of the kings known as padimagalir, some women acted as peacemakers etc.