Akershus Castle and Fortress, Oslo Akershus Castle and Fortress is an old castle built to protect Oslo and Norway. Its construction work began in 1929 under the rule of King Hakon V. This medieval castle whose work was completed around the 1300’s held a lot of importance due to its strategic location. It protected Oslo as well as Norway from a number of attacks through the ages.turkeyarena.com It was renovated by King Christian IV in the Renaissance era and had become the residence for the Royal family. The castle was in a bad shape during the 17th and 18th century till refurbishment work started in 1899. Address: Akershus Festning, 0150, Oslo Tel: +47 23 093 917 Fax: +47 23 095 670 Opening Times: Mon – Sun 06:00 a.m. - 9:00 p.m.