San Francisco’s Mosaic Staircase. Hidden art gem in San Francisco; head to and Moraga to discover The Avenue Tiled Steps. Not only will you be able to see some amazing views of the city, you'll get to appreciate a beautiful mosaic running up 163 steps.
Art Nouveau Tour of Barcelona. This is Casa Batllo, designed by Gaudi. Spain was not drawn into WW I and as such during that time, had prosperity. As as result, there are over 400 Art Nouveau structures in Barcelona.