Paris for 31 percent of the GDP of France. According to the Economist Intelligence Unit Worldwide Cost of Living Survey in 2018, Paris was the second-most expensive city in the world, behind Singapore and ahead of Zurich, Hong Kong, Oslo and Geneva. The city is a major rail, highway, and air-transport hub served by two international airports: Paris-Charles de Gaulle (the second busiest airport in Europe after London Heathrow Airport with 69.5 million passengers in 2017) and Paris-Orly. Opened in 1900, the city's subway system, the Paris Métro, serves 5.23 million passengers daily, and is the second busiest metro system in
Berlin Brandenburg Airport into operation on 16 March 2018. The U-shaped terminal building of Berlin Brandenburg Airport was designed by gmp architects. They are the same company which designed the hexagonal Terminal A at Tegel Airport which opened in 1974. At BER the terminal sits between the two runways, creating a so-called "midfield airport" above the underground train station. The terminal has four public levels designated 0, 1, 2 and 3. The check-in area is located in the public area at Level 1 and houses 118 counters organised in eight clusters, called "check-in isles". Planners anticipate that a significant number of passengers will