Nidaros Cathedral is the only Gothic cathedral located in the northernmost part of the world. The cathedral was built in 1070 AD, over the tomb of St. Olav, who brought Christianity to Norway, and was completed around 1300 AD. In the summer months you'll be able to climb the steeple with its 172 steps to the top, which is dark and narrow, but the climb is well worth it because you'll be rewarded with an unparalleled view of downtown.