The small number of basic origami folds can be combined in a variety of ways to make intricate designs. The best-known origami model is the Japanese paper crane. In general, these designs begin with a square sheet of paper whose sides may be of different colors, prints, or patterns.
On 30 June 2017 the city-state of Berlin had a population of 3.69 million registered inhabitants in an area of 891.85 km 2 (344.35 sq mi). The city's population density was 4,048 inhabitants per km 2. Berlin is the second most populous city proper in the EU.
The City of Paris is but the core of a built-up area that extends well beyond its administrative limits. Commonly referred to as the agglomÃ©ration Parisienne, and statistically as a unitÃ© urbaine (a concept similar to an 'urban area'), the agglomeration has a 2013 population of 10,601,122, which makes it the largest in the European Union.