Klondike: The buildings are quite consistent with SF, which has its own version of Carnival (see
http://www.carnavalsf.com/index.php ), most recently held last May. They spell it differently, but you'll get a lot of hits searching for " 'san francisco' carnival." It's not exactly a copycat of Brazilian versions, since there's a long tradition of Lent festivals in (especially Catholic) Christian practice: the Latin "carne" being "meat" and "vale" being "farewell." Mardi Gras and the subsequent Fat Tuesday celebrations are another example. None of these is as raunchy as Brazil's, but as your photographs and Pedro's of the Notting Hill event in London show, there's a bit starting to creep in scattered among the more family-friendly fare.