The Preesall site is a strategically important halite (rock) salt body in the UK due to its size and location. It is one of the few known suitable sites in the UK than can accommodate gas storage in salt caverns.

Storage of gas within salt is restricted to areas like Preesall where the salt is sufficiently thick to create caverns. Further, the Preesall halite salt has been extensively investigated and geological surveys have found it to be ideally suited for storing gas.
The depth of the Preesall salt bed is around 1,000 feet (300 metres), allowing gas to be stored at approximately the same pressure as the National Transmission System (NTS), a network of gas pipelines across the UK, ensuring a fast and efficient flow of gas between the caverns and the NTS.
The Preesall site is one of the last few known suitable locations in the UK that is capable of storing gas in salt caverns