St Albans before the sinkhole
A sinkhole some 20m wide opened up overnight in Fontmell Close, St Albans, on 1 October 2015. Aerial photography from 1971, accessible on the NCAP website, shows the same area before the street was built.
Visible on the photography is a cluster of industrial buildings in the area where Fontmell Close now stands; geologists believe that a brickworks was located on the site and that the void may have opened up as a consequence of the former extraction of clay there.
Aerial photography of St Albans between 1972 and 1990 is also available online, as a result of a recent public-benefit partnership between NCAP and Hertfordshire County Council, which has enabled the digitisation and upload of over 6,000 aerial images, covering the entire county, to the NCAP website.