Miami city in Florida state of the US broke Brazil's Guinness record for the tallest sandcastle in the world, the media reported on Tuesday.Guinness representatives conducted an official measurement of the sandcastle, in southern Miami's Virginia beach on Monday and certified it as the world's tallest at 15.87 metres, EFE news reported.The previous record was held by Brazil's Rio de Janeiro city, which constructed a sandcastle standing 11.63 metres in November 2014.More than 1,800 tonnes of sand was used to build the sandcastle that has etched on it the "wonders" of the world, including the Eiffel Tower and the Great Wall of China.