Springs occur where a ridge of permeable rock - in this case chalk - lie above impermeable matter- gault clay in this case. Ground water soaks into the chalk and on reaching the clay will exit along the line of least resistance. Springs which formed were obviously a valuable source of water and the settlements, often linear in character developed many hundreds of years ago. These are known as spring line settlements.
Reigate was established as a result of the siting of these springs. The chalk scarp slopes themselves traditionally were used for the grazing of sheep and any gaps in the scarp slopes would be used as a line of communication i.e The A22 near Godstone. Most of the roads still run East/ West as does the distribution of settlements .
Many of the springs would run dry during the Summer months and some form of storage would be required to quench the thirst of the local population and grazing stock. Traditionally, especially on the South Downs, Dew ponds were constructed, basically an excavated pond in the chalk lined with impervious clay. More recently other measures were introduced to store water such as found at the cache site.
The cache box must be secured properly to ensure that the contents remain dry. Access from above via Margery Lane car park - steep/muddy but outstanding view or from below via the pilgrims way -Underhill Park Road (rather muddy)