Complex sentence: After World War II and the Austrian State Treaty which was signed in 1955 the demolished castle was rebuilt and in 1958 the military academy was again located in Wiener Neustadt after a short intermezzo (1955--1958) in Enns.
Split into simpler sentences: After World War II and the Austrian State Treaty which was signed in 1955, the demolished castle was rebuilt. In 1958, the military academy was again located in Wiener Neustadt after a short intermezzo (1955--1958) in Enns.