The Cook Islands is probably the last country that anybody would think of for caves: it's a tropical archipelago of small islands in the middle of the Pacific Ocean.

However, two islands have substantial cave systems: Atiu and Mangaia.

Atiu receives more tourists and has fewer caves, and has tourist caves. More worth an exploratory trip is Mangaia. With a population of 499, and shrinking, exploration should be more 'neighborly permission' than 'closed to tourists'.

There have been a few visits by cavers, for some exploration, and some archeology. There's one article, and one cave photo, available online, with a handful of entrance shots in YouTube videos.

However, I'm confident that Mangaia's cave systems have neither been fully explored or fully mapped. They certainly haven't been photographed.

What better place to rent a bungalow for a few months and document one of the world's most isolated cave systems?