Modern skyscrapers are built with steel or reinforced concrete frameworks and curtain walls of glass or polished stone. They utilize mechanical equipment such as water pumps and elevators. From the 1930s onwards, skyscrapers began to appear around the world – also in Latin America (such as São Paulo, Rio de Janeiro, Buenos Aires, Santiago, Caracas, Bogotá, Mexico City) and in Asia (Tokyo, Shanghai, Hong Kong, Manila, Singapore, Mumbai, Seoul, Kuala Lumpur, Taipei, Bangkok).
Immediately after World War II, the Soviet Union planned eight massive skyscrapers, with seven of them actually getting built until 1953, dubbed the «Seven Sisters of Moscow». Other skyscrapers in the style of Socialist Classicism were erected in East Germany (Frankfurter Tor), Poland (PKiN), Ukraine (Hotel Ukrayina), Latvia (Academy of Sciences) and other countries. The western countries of Europe also began to permit taller skyscrapers than before WW2, such as Madrid during the 1950s (Gran Vía). Finally, skyscrapers also began to be constructed in cities of Africa, the Middle East and Oceania (mainly Australia) from the late 1950s on.