Sizihwan Tunnel

Also known as Shoushan Cave (壽山洞), this 260 meter-long pedestrian tunnel was dug through the hillside under Umino Sanjirō (海野三次郎) in 1927 and completed the following year as part of urban planning for improving access to Shoushan Park (壽山公園). Under American bombing late in World War 2, it served as an air raid shelter, and the army’s 23rd Sea Raiding Squadron is said to have laid rails through it to hide maru-ne attack boats, the army counterpart to the navy shinyo stationed elsewhere around the harbour. Branch tunnels run some 400 metres in total, several of them cut after the war as shelter for 2,150 people, one carrying an escape shaft pitched at 70 degrees to the hillside above.