Berlin Observatory
The construction of the new Berlin Observatory proceeded from a cabinet order of 10 November 1830 according to the design of Schinkel. An approximately one hectare plot was acquired at a price of 15,000 Thalers in the present-day area of Berlin-Kreuzberg. The foundation stone was laid on 22 October 1832 and the observatory was ready by 1835, on the area currently bounded by the streets ″Friedrichstraße″, ″Besselstraße″ and ″Lindenstraße″. The southern end of the ″Charlottenstraße″ was later named ″Enckeplatz″ in honor of the director at that time and the observatory acquired the address of Enckeplatz 3 A (now: ″Enckestraße 11″).
Berlin
In the early 20th century, Berlin had become a fertile ground for the German Expressionist movement. In fields such as architecture, painting and cinema new forms of artistic styles were invented. At the end of the First World War in 1918, a republic was proclaimed by Philipp Scheidemann at the Reichstag building. In 1920, the Greater Berlin Act incorporated dozens of suburban cities, villages and estates around Berlin into an expanded city. The act increased the area of Berlin from . The population almost doubled and Berlin had a population of around four million. During the Weimar era, Berlin underwent political unrest due to economic uncertainties, but also became a renowned centre of the Roaring Twenties. The metropolis experienced its heyday as a major world capital and was known for its leadership roles in science, technology, arts, the humanities, city planning, film, higher education, government and industries. Albert Einstein rose to public prominence during his years in Berlin, being awarded the Nobel Prize for Physics in 1921.