London, England (CNN) -- Dieter Roth is better known for his artist's books and paintings made of rotting food including cheeses, yogurt and chocolate.
But for three summers in the 1970s the late Swiss-German artist catalogued and photographed every building in the Icelandic capital of Reykjavik.
Twenty years later he did it again, but in winter. Capturing the city in its winter light and documenting the changes to the city.
Now an exhibition entitled "Reykjavik Slides," which brings together the 31,035 slides taken during the project, has opened in London.
Bjorn Roth, son of the late artist, who worked on a number of his father's projects including "Reykjavik Slides," was in London for the opening of the exhibition.
"When my father came to Iceland he found the architecture and houses of Reykjavik interesting and different from what he had seen before," he said.
"First he thought they were ugly, compared to what he thought of as beautiful buildings.
"But slowly he saw the beauty in the architecture and started to admire it. In the end he wanted to have a collection of it, or include it in his works."
Roth moved to Iceland after marrying an Icelandic woman in 1957 -- and lived there intermittently until his death in 1998.