The white rock is a mixture of silica, pumice, clays with the yellow being elemental sulphur. 

To the left of the bridge there is a crack in the surface containing hot black water.  This pool is approximately 80oC and is black in colour because of a large graphite deposit some 100m below the surface.

When you look at the hot pools in this area and throughout our thermal park the pools are physically very close to each other but have different temperatures and colours- this is due to the fact that each pool was the site of its own eruption and the pools are separated by geothermal mud.

Click here to view another Hells Gate Attraction - Kakahi Falls, the largest hot water fall in the Southern Hemisphere!