If Waiheke Island is becoming a tad crowded for you these days, then you might want to consider buying one of New Zealand's most isolated baches.

The two-bedroom cottage Kidney Fern is now for sale on remote Stewart Island, located south of Invercargill on one of the last stops before Antarctica.

Valued by the council at $500,000, the holiday home can only be reached by a two-hour hike or 15-minute water-taxi ride from the island's only town, Oban.

And it is so remote, the real estate agency selling the property hasn't been able to get a professional quality picture of it for its online listing.

Coastal waters near the small cottage on Stewart Island. Photo / Supplied

It has no electricity, no running water and no mobile phone coverage. Contact with the outside world can only be made using a battery-powered radio.

Heat for cooking and warmth comes from coal and gas carried to the bach in bottles, while the toilet is an "eco-friendly long-drop".

A Stewart Island fisherman and guest house operator bought the place in 1970 as a holiday home away from the "hustle and bustle" of Oban and its population at that time of about 270.

"Over the ensuing decade, weekends and summers were spent at the secluded cottage,
where the children fished for blue cod off the beach and picked mussels off the rocks at the end of the front lawn," Bayleys Real Estate selling agent Mike Peterson said.

Holidays also included cutting firewood for the barbecue, fishing, stargazing and tramping into the Rakiura National Park.

The family moved off the island in 1981 but regularly returned to Kidney Fern for the tranquillity and solitude.

"Kidney Fern truly was, and is, the essence of what it was to be a Kiwi kid," Peterson said.

"And nothing much has changed since then. The cottage is in pretty much the same state it was when the family enjoyed it as children."

The cottage has views over two beaches and sits on about 221ha of waterfront land, bordering the Rakiura National Park – New Zealand's southernmost wilderness reserve.

It also the southernmost property Bayleys has ever marketed for sale.

The sale price is up for negotiation.