Te Waikoropupu Springs also known as the Pupu Springs, it is the largest, clearest of New Zealand's freshwater springs. The basin containing the main spring is 42 metres across, and through a system of mirrors scientists have recorded the horizontal visibility at 62 metres (203 feet) a world record - the springs are considered to be the clearest fresh water in the world.
- The only place known to have greater clarity is under the Ross Sea Ice Shelf in Antarctica
- 14000 litres of water per second is discharged on average.
- The water stays underground between 2-10 years before being forced out.