Nakanai Mountains

The Nakanai range runs along the interior of New Britain, a block of limestone lifted and cut by extremely high rainfall into one of the great karst landscapes: rivers disappear into shafts, enormous dolines drop hundreds of metres through the forest, and cave systems carry underground rivers of very high flow, including passages that rank among the largest by volume anywhere. Minye, Naré and Ora are among the named dolines, explored by French, Italian and other expeditions since the 1980s. The range is on Papua New Guinea's tentative World Heritage list as part of the Sublime Karsts. Reaching it means expedition logistics, landowner agreement and guides from the villages.

History

Finds near Yombon show people living on New Britain as early as 21,000 BC. William Dampier was the first known Briton to visit, on 27 February 1700, and named the island Nova Britannia; whaling ships called here through the 19th century, the first on record the Roscoe in 1822, and under German rule from 1884 the island was called Neupommern (Wikipedia, New Britain).

What you'll find

• The dolines - the vast sinkholes dropping through the forest.
• Underground rivers - the high-flow systems inside the karst.
• Cave passages - the very large chambers explored by expeditions.
• Rainforest karst - the limestone landscape under continuous forest.

When to go

May to October is marginally drier, but this is one of the wettest places on earth and flooding in the caves is a constant hazard. Expeditions take months to arrange with landowners and logistics.

What to expect

This is expedition caving country, not a visitor destination: no infrastructure, no marked routes, and access entirely dependent on landowner agreement. Cave flooding is lethal and rain is near constant. Costs and logistics are substantial.

Nearby

The north coast road lies below; Rabaul is northeast.

Key facts