Rabaul

Rabaul is a town that grows on you slowly, or not at all, depending on what you came looking for. It sits inside the Simpson Harbour caldera, a vast flooded volcanic crater ringed by steep green hills, and the first thing you notice is how the landscape feels wrong for a town — the harbour is too large, the surrounding peaks are too steep, and the sea is too close on all sides. This is not a city that made itself comfortable with its geography; it grew up inside a geological accident and has never quite settled the argument.

The town was the capital of the Australian-administered Territory of New Guinea from 1910 until 1941, and it bears the physical marks of that history in abundance. The Japanese occupied Rabaul from January 1942 to August 1945, and the surrounding hills and jungle are still dense with the remnants of airfields, tunnels, bunkers and gun emplacements. An estimated 100,000 Japanese personnel were stationed here at the peak of the Pacific campaign, and the seabed holds one of the densest concentrations of aircraft and shipwrecks in the world — many of them in remarkably accessible shallow water. The water temperature is warm year-round, visibility in the volcanic harbour regularly exceeds twenty metres, and each new discovery of a previously unknown wreck adds to the inventory.

The dual eruption of Mount Tavurvur and Mount Vulcan in 1994 destroyed much of the town and buried the airstrip in ash, and the visible damage to the townscape — corrugated iron roofs patched with new metal, walls still showing blast scarring, buildings half-rebuilt and then abandoned — is a reminder that the geological argument has not been settled. Tavurvur remains active, releasing slow plumes of steam and ash that drift across the harbour most mornings, and the hot springs at the base of the caldera are in continuous use by local people as thermal bathing pools. The sulphur pools near the old airport are particularly striking: yellow-green mineral crusts around vents that smell of hell and feel like paradise.

For divers, Rabaul is one of the world's more extraordinary destinations. For non-divers, the WWII heritage in the surrounding hills, the vantage points on the caldera rim, and the geothermal strangeness of the hot springs and sulphur pools are compelling enough. Rabaul is not a place that makes concessions to visitors; it expects you to meet it on its own terms, and those who do tend to find something they did not expect. The town has become a base for a small community of volcanologists, wreck researchers and dive professionals who return year after year, and their enthusiasm is infectious when you sit with them over a drink at the Rabaul Hotel and watch Tavurvur's glow above the harbour at dusk.

It sits inside a live volcanic caldera with active vents, hot springs and sulphur pools that make the geological setting part of everyday life.

The surrounding hills and seabed hold one of the world's densest concentrations of WWII aircraft and ship wrecks, with exceptional diving conditions.

The pre-war and wartime heritage buildings, tunnels and fortifications are among the most extensive in the Pacific.

The 1994 eruption and its aftermath are visible throughout the town, giving a layered human story to the volcanic landscape.