Kristiansten Festning or the Kristiansten Fortress is a magnificent fortress, built after the fire of 1681, that boasts of a strategic location. Constructed with an aim to fortify the city from the east, the fortress held a lion's share during the Swedish invasion of 1718. Besides pleasing military buffs, the fortress also entices architecture enthusiasts with its marvelous plans as also with its innovative nine-sided design. For those who are not interested in tracing the fortress' history or appreciating its architecture, the Kristiansten Festning offers breathtaking views of its scenic environs. Visit once to explore the place.