Eth Pokuna is a massive pond in Anuradhapura. It is situated off of Lankaramaya and connected to the gigantic Abhayagiri Monastic Complex. This is 159 meters in length 52.7 meters across and 9.5 meters in-depth with the holding capacity of 75,000 cubic meters of water.
Eth Pokuna remains as one of the most intriguing historical places in Sri Lanka thanks to the incredible level of hydraulic engineering that was used in its creation. Water flowed in from the nearby Periyankulama Tank and bits of piping are still visible today.
These underground canals still work after so many hundreds years and in 1982 after a very heavy rainy season you could see water pouring though these inlets from the Periyamkulama tank.
This tank probably has been used by the monks in the Abayagiri monastery who amounted over five thousand priests.