Høytorp fort was the main fort in Fossumstrøkets fortress and is built in the period 1912-1918. First contingent of recruits arrived Høytorp Fort on August 10, 1915. The fort took part in battles against German forces 9-14. April 1940. The fort was abandoned as a military facility in 1994, protected by the Cultural Heritage 2001 and transferred to Eidsberg municipality in 2003. During the war the Germans removed the fort's four towers cannons, and the Association for Høytorp fort has since 1996 worked to get the tower cannons back. In 2009, portions of the first two 7.5cm Cockerill tower guns were back, and these were assembled in 2014. A 12 cm Schneider turret gun was dismantled and taken in 2014, and was assembled on Høytorp fort in July 2015 so that the was ready to the 100th anniversary of the fort. Thus, three out of four turret guns reversed. 12cm tower cannon is effective, and fired at each event. See our website or Facebook for more information about when you can experience the gun roar. In the area are over 40 buildings which today houses restaurant, handicrafts outlets, crafts, flea market and more. The area is open to the public every day. Guided tours every Sunday 14.00 in June, July and August. There will be guided in ca. 90 minutes through dark exciting tunnels, inside and outside, the tower cannons, hear interesting history and enjoy great views from the top of the mountain resort. Tour ends in an exhibition of uniforms, weapons and items. A separate artillery museum is open from kl. 12:30 to 13:30 every Sunday in June-August. Kanon exhibition is in building 11, and consists of cannons from 1870 - 1944. Its restored continuously by the Association for Høytorp. Fixed annual events: Spring days (April) pre x-mas days (November) and meeting for military historical vehicles (August). There salute (21 shots with guns) from the fort on 17 May.