Abel Tasman is New Zealand's smallest national park and consistently its most visited — a sixty-kilometre coastline of golden-sand beaches, granite headlands, and clear turquoise water at the northwestern tip of the South Island. There are no roads inside the park; you arrive by walking in from Marahau at the southern end or Totaranui at the northern end, by sea kayak, or by water taxi from Kaiteriteri.
The headline experience is the Abel Tasman Coast Track, one of New Zealand's nine Great Walks. It runs the length of the park along the coastline, typically over three to five days, with DOC huts and campsites spaced along the route. You do not have to walk all of it — the water taxis from Kaiteriteri and Marahau will drop you at any beach and pick you up at another, so a single-day sampler is easy. The pick of the beaches — Anchorage, Bark Bay, Torrent Bay, Awaroa, Totaranui — are among the finest in New Zealand, sheltered and warm by South Island standards.
Sea kayaking is just as good as walking and arguably better for seeing the park's wildlife. The protected coastline, the variety of landing beaches, and the Tonga Island Marine Reserve with its fur seal colony make this one of the best coastal kayaking environments in the country. Multi-day kayak-and-camp trips can be combined with sections of the Coast Track for a mixed itinerary.
The park sees most of its visitors between December and February, when the huts and campsites book out months ahead and the beaches can feel busy. Shoulder months — November and March — give you the same weather with a fraction of the people. Winter is quiet, often clear, and surprisingly cold in the early mornings; some water taxi services run a reduced schedule but the track itself stays open all year.