Rabaul is a township on the island of New Britain in Papua New Guinea's East New Britain province, situated on the edge of the Rabaul caldera — a flooded volcanic caldera roughly 600 km east of the New Guinea mainland. The town is built around Simpson Harbour, a dramatic natural anchorage that doubles as the caldera's flooded interior, making it one of the Pacific's most geologically active settings. In 1994, a volcanic eruption sent ash thousands of metres into the air and caused approximately 80% of Rabaul's buildings to collapse, effectively ending its role as a provincial capital and shifting that status to nearby Kokopo. Beneath and around the ruined townsite lies an extraordinary legacy of World War II occupation: the Imperial Japanese military is said to have constructed hundreds of kilometres of underground tunnels throughout the area, and the harbour itself is a graveyard of sunken wartime wreckage. Gates came to Rabaul in Expedition Unknown's debut episode while chasing leads in the Amelia Earhart disappearance mystery, investigating both jungle aircraft wreckage reported by a local tribe and underwater wreckage in the harbour.
Germany establishes administrative control over the region as part of German New Guinea.
Rabaul is selected as the capital of the German New Guinea administration.
Administrative offices formally transferred to Rabaul; the town is planned and built around Simpson Harbour.
Rabaul captured by the British Empire in the early days of World War I; later becomes capital of the Australian-mandated Territory of New Guinea.
Rabaul is first severely damaged by volcanic activity.
Japan captures Rabaul and establishes it as its main base of military and naval operations in the South Pacific, reportedly garrisoning over 100,000 troops and constructing extensive underground tunnel networks.
A volcanic eruption causes catastrophic ash fall, collapsing approximately 80% of Rabaul's buildings and forcing the relocation of the provincial capital to Kokopo.
Josh Gates investigates Rabaul as part of Expedition Unknown Season 1, Episode 1, chasing Amelia Earhart leads.
Rabaul's significance during World War II is well established by mainstream historians. After Japan seized the town in January 1942, it became the headquarters of the Eighth Area Army and a critical hub for Imperial Navy operations across the South Pacific. The scale of the Japanese military presence was enormous — the garrison is estimated to have reached over 100,000 troops at its peak — and engineers constructed an extensive underground tunnel system throughout the caldera rim to protect personnel and equipment from Allied air raids. These tunnels, said to extend for hundreds of kilometres, remain one of the most tangible physical legacies of the Pacific War in the region.
The harbour itself, Simpson Harbour, is a well-documented underwater archive of wartime wreckage. Allied bombing campaigns and the eventual end of the war left dozens of Japanese ships, aircraft, and materiel on the seafloor. Scuba divers and maritime archaeologists have explored these wrecks for decades, and they are regarded as significant cultural heritage sites reflecting the cost of the Pacific conflict. Rabaul is considered one of the Pacific's premier wreck-diving destinations precisely because of this density of submerged history.
The Amelia Earhart connection that brought Gates to Rabaul is far more speculative territory. No credible mainstream evidence places Earhart's Lockheed Electra anywhere near Rabaul, and the historical consensus holds that Earhart and navigator Fred Noonan most likely went down in the central Pacific near Howland Island in July 1937. Various researchers have pursued competing theories — crash-and-sink near Howland, a landing on Nikumaroro Atoll, and Japanese capture scenarios among them — but none have produced definitive physical proof. Aircraft wreckage found in tropical Pacific environments is not uncommon given the intensity of WWII air operations, and any wreck identified in Rabaul's harbour would require rigorous forensic analysis to connect it to Earhart's specific aircraft.
Gates' Season 1 debut episode was candid about the investigative nature of the visit: the episode explores whether leads pointing to Rabaul could shed light on the Earhart mystery, and the on-camera discovery of what appeared to be aircraft wreckage in the harbour generated genuine excitement. However, the episode does not claim to have resolved the mystery. The Rabaul sequences contribute colour and context to an ongoing cold case while also documenting the WWII tunnel network and the Baining tribe's jungle wreckage reports — layers of Pacific history that stand on their own merits regardless of the Earhart question.
The volcanic eruption of 1994 caused approximately 80% of Rabaul's buildings to collapse under falling ash, effectively ending the town's role as East New Britain's provincial capital.
Simpson Harbour, Rabaul's natural anchorage, is actually the flooded interior of the Rabaul caldera — a large pyroclastic shield volcano.
Rabaul has been devastated by volcanic activity more than once: the town was first severely damaged by a volcanic eruption in 1937, years before its wartime destruction.
Despite its reduced state, Rabaul attracts 10 to 12 cruise ships per year, including vessels carrying up to 2,000 passengers, drawn by its diving, WWII history, and dramatic harbour scenery.
Rabaul is generally accessible to visitors, with most travellers routing through Kokopo or flying into Tokua Airport on New Britain. The WWII tunnels, the ruins of the old township, and Simpson Harbour's dive sites attract history buffs and divers from around the world, and the area receives approximately 10 to 12 cruise ships annually. Travellers should check current local advisories regarding volcanic activity, as the Rabaul caldera remains geologically active.
Kokopo, approximately 20 kilometres from Rabaul, is the current provincial capital and the nearest significant urban centre.
Papua New Guinea's dry season, roughly May through October, is generally considered the more comfortable period for travel and outdoor exploration. Diving conditions in Simpson Harbour can be good year-round, but visibility tends to be better outside the wet season.
Normandy Beaches, France
Like Rabaul, the Normandy Beaches represent a major World War II theatre that Gates has investigated, exploring the physical remnants and human stories left behind by the conflict.
Lake Otjikoto
Lake Otjikoto is another body of water investigated by Gates for submerged WWII-era military equipment — a direct parallel to the underwater wreck-diving component of the Rabaul episode.
Dyatlov Pass
Dyatlov Pass, like the Earhart mystery that brought Gates to Rabaul, is an iconic unsolved disappearance case that Expedition Unknown has pursued — connecting these sites thematically as cold-case investigations into famous vanishings.
Historical data sourced from Wikipedia