Patek Philippe Calibre 89, the 20th century's most complicated watch, heads to auction

On May 14, one of only four existing Patek Philippe Calibre 89 watch/clocks goes on auction for the first time since 2009. Made to celebrate the 150th anniversary of Patek Philippe, the Calibre 89 has 33 complications or functions, making it the most complex watch constructed in the 20th century.

Source: Patek Philippe Calibre 89, the 20th century’s most complicated watch, heads to auction