This puzzle recreates Berlin‎'‎s historic skyline‎,‎ not only in three‎-dimensions‎,‎ using scale‎-model buildings‎,‎ but also along the fourth dimension of time ‎- spanning over 700 years of architectural history‎.‎ The puzzle includes 138 building replicas that depict Berlin‎'‎s Skyline as it appeared as far back as 1292‎,‎ through to 2006 with the completion of Hauptbahnhof‎.‎ The puzzle includes such iconic structures as the Marienkirche‎,‎ Friedrichstraße‎,‎ Checkpoint Charlie‎,‎ and Kollhoff Tower‎.‎ In 1961 you replicate history as you build the Berlin Wall using 60 replica pieces‎.‎ In 1989‎,‎ you remove the wall as you re‎-join East and West Berlin together‎.‎The base of the puzzle is a traditional 2D jigsaw puzzle that forms the city‎'‎s street layout and geography‎.‎ During the process of constructing the base map‎,‎ one learns about Berlin‎'‎s neighborhoods‎,‎ streets‎,‎ museums‎,‎ and more‎.‎ Once the puzzle base is complete‎,‎ the vertical building of Berlin‎'‎s Skyline begins by placing 138 buildings and structures in chronological time sequence‎.‎ This is done by following the enclosed 4D Time Poster‎.‎