Chislehurst Caves

The London Basin is an elongated and roughly triangular syncline approximately 160 miles long, which underlies London as well as a large area of south east England and south eastern East Anglia. The substructure of the layers below the surface was first charted in the 19th century due to the need for drawing fresh water for drinking to replace the contaminated water of the Thames. During this time the layers were noted as sands and gravels, blue 'London' clay, clays and sands and the 'Lambeth group' which was made up of chalk and flints. It was chalk in particular, with its ability to absorb rainwater, that was siphoned off to provide the clear drinking water for London's inhabitants. Chislehurst Caves, a 20 mile labyrinth of man-made tunnels, is where a fine example of this chalk substructure can be found.

This vast complex of caves are a maze of ancient mines originally carved out in the search for flint and chalk. Divided into three main sections, it is thought they are derived from the Saxon, Druid and Roman eras, each section later connected by digging adjoining passages. Chalk has been important to civilisations over thousands of years and still is to the present day. Mining chalk provided lime and flint. Lime, the basis for plaster and whitewash paint and flint for the manufacture of tools by early man and later for building. Although difficult to date, the mines appear on a charter of 1250 as well as in local church records of 1737.

The caves became the setting for several underground concerts in the early 1900's and during World War I became part of Woolwich Arsenal and used as an ammunitions depot, with a narrow gauge railway installed to aid transport throughout the passages. The caves were used by the Kent Mushroom Company up until the outbreak of World War II, however, with the constant onslaught of bombings over London, this massive network of tunnels, which was within easy reach of the capital and its main suburbs, was deemed the ideal location for a huge air raid shelter. Housing up to 15 000 people at a time it was a complete underground community comprising of churches, a hospital, the country's first permanent Citizens' Advice Bureau, shops and even Scout and Guide troops. A dedicated and reliable rail service from Cannon Street station in the City served the shelter nightly.

During the 50's 60s and 70s the caves became a popular music venue hosting some of the biggest names of the day in jazz and rock including The Who, Jimi Hendrix and the Rolling Stones. Because of the unique acoustics it was possible to hold several concerts at once in separate locations without them interfering with each other. In October 1974 the caves housed a lavish media party, held to celebrate the launch of new UK record company Swan Song Records by the band Led Zeppelin.

Chislehurst Caves remain a source of fascination for all ages and a major London tourist attraction.