This is a geothermal area with a geyser, a bubbling mud pool and an extensive area of geothermal features.
Click on a picture for a larger version.

Lady Knox geyser

Erupts at 10.15am every day...

...with a little help...

...from 300g (10oz) of laundry detergent

Which takes a minute or two to work

But the end result is spectacular

Visitor Centre with geothermal field behind

For the foreign tourists

Devil's Inkpot

Opal pool

Sinter crust

Crystals forming

Sulphur crystals around a fumarol (gas vent)

Preserved area of native forest

Distant cooling tower is a geothermal power station

The always fun bubbling mud