Complex sentence: At the time, Kaunas Fortress was also being constructed around the city, all the buildings were limited to a height of 2--3 floors, with a few exceptions such as St. Michael the Archangel's church, built in 1895.
Split into simpler sentences: At the time, Kaunas Fortress was also being constructed around the city. As a result all the buildings were limited to a height of 2--3 floors, with a few exceptions such as St. Michael the Archangel's church, built in 1895.