Russian Army Headquarters and Maritime Fleet planned to build a sea and land fortress, and Major General Ivan Alfred McDonald developed a project on August 30, 1892. Near Naval Port and the Lake Tosmare Apparent Heir’s Grove and residential buildings with streets were built. Residential buildings were built in “New World” – land between Romny Railway and Grobin Highway. In Liepaja 1922 administrative border plan development was started to include the Lake Liepaja’s northern part into the urban territory. Low-rise residential buildings of Aspazija’s (former Apparent Heir’s) Grove were supplemented. Research issue – building structure and development of residential buildings of Libava Maritime fortress territory has been studied insufficiently. Novelty characteristics – low-rise residential buildings’ construction and street network of Apparent Heir’s Grove has been analysed. Research goal – analyse “New World” and low-rise residential building and planning of the Lake Tosmare surroundings till World War II. Principal research methods – planning and construction observation in nature, archive and cartographic material analysis. Brief description of research outcomes: fortress built on the Baltic Seacoast affected further development of the territory. Nowadays development of qualitative architectonic space without historical development analysis is impossible.