I did 3 or 4 days stop over in Santiago Chile and loved it, highly recommend "W" hotel there. Great and affordable local high end fashion boutiques in 20 min. walking distance. Great food and wine. Friendly people. One of the underground stations named after Einstein
Take a funicular up San Cristobal Hill, great experience and unparalleled city vista. Presidential La Moneda palace with horse guards. Garcia Lorca house and much more. Great views from the plane of rusty copper land. Easy hop to Buenos Aires in half empty plane. Go for it!