I am going to Cancun for xmas then travelling on to Peru..in the uk it is impossible to obtain this currency will it be easy enough to get in cancun? as I know Cancun airport does not even change sterling.
I've never seen any cambios deal in Peruvian currency (the nuevo sol). There's next to no call for it. Probably best to wait until you get to Peru and take some US$ to last you long enough to find somewhere to exchange.
