Casnell Island is an uninhabited island in the Mahurangi Harbour in the Auckland region. The island is managed by DOC and is the largest island in the harbour.
The island is south of the east end of the beach at Scotts Landing, between the Te Kapa River mouth and Mahurangi Harbour. As the tide retreats, it is an easy 100-metre walk over a shell and sand causeway to the rocky platform around the island. If you wander along the west side, you will see a steep grass-covered gap in the cliffs, with a single step up. The path may not be obvious, as the grass is very long, but you can push your way through to the scrub and trees, where it is easier to spot the track, which runs the length of the island.
The track is a mix of forest regrowth, mostly kanuka and kōwhai, and more open, grassy areas. There are also several mature, large pōhutukawa trees. There are lovely views over the harbour and river from the cliff's edge at both ends of the island. Take care, as there is no protection near the edge.
Casnell Island was a pā site in the 1700s, with a strategic position in the harbour, and you may notice some signs of its historic role.
