Champagne goes to Charlotte Singer of City Centre Concepts, London, for correctly identifying Felix Candela's Cosmic Ray Pavilion at the University of Mexico as the odd one out. Images 1 and 3 are united by a Chile connection. Image 1 is Chile Haus, Hamburg by Fritz Hoger, and image 3 is former Chilean dictator General Pinochet.
Apologies for last week's incorrect assertion that Ginger Rogers has a 'd' in her surname.
To win a bottle of champagne, send answers on an odd postcard by first thing Monday morning please to: AJ Astragal, 151 Rosebery Avenue, London EC1R 4GB or, in an emergency, fax your answers on 020 7505 6701.