See all Attractions in Rabaul Rabaul for: Adventure, Food And Dining, Art And Culture, Nightlife, Spa, History, First Timers, Family, Romance, Shopping Japanese Tunnels. About Japanese Tunnels. There are around 700km of tunnels in the hills that surround Rabaul's Simpson Harbour. Accommodation, hospitals and hiding places for barges were built in them. Some of the barges can still be seen in tunnels at Karavia. Add to Wish List
