Task: Question Generation
Input (English): Paris' urbanism laws have been under strict control since the early 17th century, particularly where street-front alignment, building height and building distribution is concerned. In recent developments, a 1974-2010 building height limitation of 37 metres (121 ft) was raised to 50 m (160 ft) in central areas and 180 metres (590 ft) in some of Paris' peripheral quarters, yet for some of the city's more central quarters, even older building-height laws still remain in effect. The 210 metres (690 ft) Montparnasse tower was both Paris and France's tallest building until 1973, but this record has been held by the La Défense quarter Tour First tower in Courbevoie since its 2011 construction. A new project for La Defense, called Hermitage Plaza, launched in 2009, proposes to build two towers, 85 and 86 stories or 320 metres high, which would be the tallest buildings in the European Union, just slightly shorter than the Eiffel Tower. They were scheduled for completion in 2019 or 2020, but as of January 2015 construction had not yet begun, and there were questions in the press about the future of the project.
Output (English): Until 1973, what was Paris; tallest building?