A photograph of a busy close behind number 46 Saltmarket in Glasgow, taken by Thomas Annan in 1868.

Groups of ragged, dirty children sit on the cobbled street and men stand around watching the photographer. Saltmarket Street crosses the High Street, which started at the east end of Glasgow where the majority of the city's slum housing was located. Overcrowding and poor sanitation made for high mortality rates caused by infection and disease. Thomas Annan was a Scottish photographer who lived for most of his life in Glasgow, where he established a studio in 1855.

In 1868 the City of Glasgow Improvement Trust approached Annan to take photographs of some of the slum areas of the city prior to demolition. The resulting images are some of the earliest examples of documentary photography.