Mount Karioi is the extinct volcano that frames Raglan's coast. The summit track from Te Toto Gorge is a serious walk, steep and muddy in places, but it gives wide views over the harbour, the surf breaks, and the west coast.
Go prepared, especially after rain. If you do not want the full climb, the roads and shorter tracks around the mountain still give a strong sense of Raglan's landscape: black sand below, green slopes above, and the Tasman Sea beyond.