Set within Marlborough's vast Molesworth Station, this riverside campsite sits beside the historic Acheron Accommodation House, a cobb building dating from 1863 that once served as an overnight carriage stop. There's plenty of space across three flat camp areas: one behind the old Acheron Lodge, one beside the DOC warden's hut (both above flood level), and a third tucked down by the river. Facilities are simple non-powered tent sites with a long drop at each level and tap water, and most visitors report good cell reception. It's an excellent base for exploring, with several walks on offer, including a worthwhile 20-minute loop from the top campsite, plus good fishing for anglers willing to walk in. The surroundings are open and scenic but exposed, so pack warm clothes as it gets colder than expected, and be ready for sandflies. Access is via Acheron Road, which opens seasonally from 1 October to Easter Monday (or the second Sunday in April, whichever is later), 7am to 7pm daily, and can close without warning.