We seek beauty in many forms--through architecture and art; water views and mountain vistas; culture and history --and a few areas make that hunt extremely easy. This listing of completely magnificent locales circles the globe, covering the towns and cities that made us fall in love at first sight with their futuristic skylines, tree-lined canals, and vibrant historic buildings (among a number of other items ). From Amsterdam to Cusco, here are the 20 most gorgeous cities on the planet.