“Kirkenes was the second-most important town in Europe during World War II,” guide Ronny Ostrem said, as he unlocked the metal door of the Andersgrotta air-raid shelter. Thanks to its location just 124 miles from Russia’s ice-free Murmansk Harbor, this small city, located in Finnmark, Norway’s largest and northernmost county, has the dubious distinction of being one of Europe’s three most-bombed cities — fewer times than Malta but more than Dresden.

“Terror came three times each night,” Ostrem said, adding a personal note. “My mother said she didn’t take off her clothes in the night for three years.” Because Kirkenes’ strategic location was considered vital to the Allied effort, Hitler stationed more than 40,000 troops here with one mission: to control the harbor and town. The Russians, of course, retaliated.

“The air-raid siren sounded more than 1,000 times, with 320 actual attacks, each with more than 100 planes; it was over in 12–15 minutes,” Ostrem said. Each time, the citizens of Kirkenes took refuge in the cave-like tunnels, designed by engineer Anders Elvebakk and built into a hillside in the city center.

The Red Army liberated Kirkenes Oct. 25, 1944, but not before the Germans retreated, burning the city behind them. Afterward, Ostrem said, those who endured the horrific conditions buried their memories. “They talked only of the future, not about what happened.”