Tunnel Entrance
As the war turned against the Japanese, and Rabaul area was subjected to daily bombing raids, many tunnels were dug into the pumice ridges for hospitals, guns, bunkers, gun emplacements, barracks and HQ.
During the early months of 1944, Japanese dug (with labor force) tunnel complexes that by November reached 70km for the Navy and 80km for the Army. By the end of the war, it was estimated these lengths doubled. Another estimate places Gazelle Peninsula tunnels at 500km in collective length.
