'overtired'......Congratulations 'Rio de Janiero' it is, the city of 'Copacabana'. You have just scored a 'hat-trick' ...... 3 in a row Challenges solved. total 10 challenges solved same as 'mushroomsteve'......... Honorary Gold Medal on it's way. :o)
I think you switch the capitals and countries of each place and take the first letter of the locations, example Australia becomes Canberra, Muscat becomes Oman etc. to spell out Copacabana