Art and photography are not usually reviewed on the site because the focus is on architecture and design but for several reasons this is an exceptional exhibition that resonates with themes discussed here on architecture and planning and is a very strong reminder of the importance of the political and social changes that are needed to resolve serious issues that emerge with large-scale migration and rapid urban growth.

Jacob Riis was a Dane who emigrated to New York with his parents in the late 19th century and worked first as a journalist and then as a photographer. He was one of the pioneers of photo journalism … using images rather than text to show people who had not realised or had not wanted to see the conditions in which huge numbers of people lived in the city tenements.

Why is the exhibition timely? Images on our television screens and in newspapers of crowded slum housing in South America or Asia or Africa seems alien and remote to most living in Europe or the USA but in reality it is only three or at most four generations ago that there were similar living conditions in not just New York but Chicago or San Francisco and in Europe in the ‘great’ cities like London or Manchester that had seen massive expansion in the numbers of migrant workers, either from abroad or escaping from severe economic deprivation in rural economies, and of course even in Scandinavia similar living conditions could be found in the crowded inner courtyards and cheaply built housing in Copenhagen and Stockholm.