Rarotonga is the main island of the Cook Islands, in the South Pacific, a worn-down volcano of jagged green peaks inside a lagoon that is waded and paddled from the shore, ringed by a single road of 32 kilometres and crossed through the middle by one track past a bare spire of rock called The Needle. The island is young enough that its reef still hugs the shore, the beginning of the sequence that ends in an atoll, so the lagoon is narrow and shallow, and at Muri on the southeast coast the warm pale water stretches knee-deep toward four low islets, Taakoka, Koromiri, Oneroa and Motutapu, paddled to by kayak or paddleboard, while much of the best snorkelling is a short swim from the sand, where coral heads scattered across the lagoon floor hold parrotfish, wrasse and the striped Picasso triggerfish. The cross-island track leaves Avatiu valley on the north coast, works up through rainforest on a trail of tangled tree roots to the base of Te Rua Manga, the Needle, where a fixed rope helps with the last steep step, and drops down the southern side to Wigmore's waterfall, a fern-hung rock face spilling into a freshwater pool where the island's children launch themselves off the ledge.
The inland road, Te Ara Nui o Toi, the Great Road of Toi, was laid in stone before the coast road and still runs through the taro fields and villages behind the shore. Between July and October humpbacks arrive from the Antarctic to breed and calve, and because deep water begins just outside the narrow reef they pass close, with mothers and calves lingering off the reef for weeks and the breaches watched from the shore road. A flycatcher found nowhere else on Earth, the kākerōri, was down to 29 birds in 1989 and has been brought back to several hundred in the Takitumu reserve, where it is walked to with a guide. Rarotonga is a mountain in a lagoon with one track over the top, and the whole island is seen from the road around it.