Barcelona artist Javier de Riba paints beautiful geometric tile designs on floors of abandoned and/or condemned buildings. The work of his series Floors takes meticulous planning and template design. His "interventions" bring both beauty and attention to public spaces that would otherwise be forgotten.
See more pictures of de Riba's painted tile floors in this gallery. Each entry has some history about the building, often a video of the process, and the design in a smaller size that can be purchased as a print.
-via Cliff Pickover