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Underground caves are natural museums where the geology and biology of past
millennia are preserved in conditions of near-constant temperature and humidity.
Unfortunately, in enjoying the exhibits, visitors can disturb this delicate
environment with every breath or step they take. David Gillieson’s introduction
to speleology, Caves: Processes, Development and Management (Blackwell,
£18.99, ISBN 0 631 19175 5) explains not only how caves are formed and
colonised, but also what can be done to maintain them for future
generations.