In 2016, the historical city centre was listed as 'endangered' by the World Monuments Watch. In 2017, Bucharest was the European city with the highest growth of tourists who stay over night, according to the Mastercard Global Index of Urban Destinations. As for the past two consecutive years, 2018 and 2019, Bucharest ranked as the European destination with the highest potential for development according to the same study. Another study estimates Bucharest to become Europe's richest city by 2050.