The world's most expensive painting, Leonardo da Vinci's 'Salvator Mundi', is kept on Saudi Crown Prince Mohammed bin Salman's superyacht Serene, a report said. It will be on the superyacht until the Saudis create a planned cultural hub in the Kingdom's Al-Ula region, the report added. The over 500-year-old artwork was sold for $450.3 million at an auction in 2017.