The Chasm

Useful Information

Location: Fiordland NP, Milford Sound Highway, off the road about 7 km west of Homer Tunnel.
Open: No restrictions.
Road may be colsed due to weather conditions.
Fee: free.
Classification: KarstLosing Stream
Light: n/a
Guided tours: slef guided, D=45min
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.



The Chasm, a rather descriptive name for what this place looks like, is actually a typical karst feature called sinkhole or loosing stream. It is a result of contact karst, which means karst located at the contact between soluble and insoluble rocks. Here the Cleddau River crosses an almost invincible border. Underground the type of rock changes, and while the rocks uphill are insoluble the water is flowing on top of the rocks in its riverbed. As soon as it reaches the limestone, the water runs through narrow cracks in the rocks, starts to solute the rock along the crack, and form caves. When the caves become bigger they will start to swallow the complete stream, at least most of the year. This is what happens here. The water is flowing into a cave with a roaring chasm.

The Chasm is a rather new sight along this road, wich was developed some years ago. Today there is a parking lot, a trail to the chasm, and a bridge across it, which allows a good view down into the swallow hole. Nevertheless, the cave behind is not actually visible, as it filled completely with water. Walking time is about 15 minutes.