Multi-coloured window jambs on an office building in central Brussels. From head on the building looks fairly normal: its only when you look up and along the walls that the hidden colours become visible.
Photo: Hidden colours, Brussels
Photo: Glass swirls
The glass front of the lobby of the Saxo Bank building, Copenhagen, Denmark.
Photo: Just climb on up - National Library of Scotland
Exterior of the National Library of Scotland, Causewayside, Edinburgh