Hochstetter Grotto Pond

A beautifully self evident reminder of Auckland's heritage as an enormous volcanic field.

Here on Grotto Street, and also hidden from view on Puka Street, are a pair of depressions almost certainly caused by the roof of cooling lava flows caving in and being carried away in the flow from the One Tree Hill Volcano. This one, turned into a pond, which is unusual for a lava cave, as water would normally find a away to flow away. The theory for the variation is that yet another volcano (Mount Smart) later filled the pond with ash, sealing the bottom. Hochsetter pond is also of ecological interest due the abundance of freshwater phytoplankton, which combines with the ash to become a substance called 'diatomite'. An interesting side story is of a small buisness that packaged this substance as 'Grotto Maid' polishing powder. At some stage the insides of the pond were lined with concrete.

The Puka Street version is smaller and forms the back yards of several private properties.

Travelling geologist Ferdinand von Hochstetter identified both 'grottos' in the 1860s, as associated with lava cave rooves having fallen in. It became a large urban section (number 36) and went into private hands. There was a classic Auckland volcanic front fence built, maybe around the turn of the century, and also a house, which is no longer there.

Though the large section is still in private ownership, there is now a move to turn Hochstetter Grotto Pond into a functioning community park.

NZPlaces would love a picture of Onehunga's Hochstetter Grotto Pond.

Photo Credit; Google Maps.