east boundaries. High Wall Extraction is a series of small mines that extract otherwise wasted stone that sits between the final faces of the quarry and the actual boundary of the site. Stonehills Mine is the first completely new mine on Portland (not a mine as an extension from an existing quarry). Albion Stone Plc began the process to open this mine in 2015 and reserves are estimated to last for 50 years (2066). Independent Quarry and Admiralty Quarry are both owned by The Crown Estate and have been leased since 1982. These quarries have been worked since the mid-19th century with the final dimension stones coming out of Independent in 2006, although some stocks of Portland stone block still remain. Coombefield Quarry, located near Southwell has been open cast quarried over the last 80 years and is one of three privately owned quarries by Portland Stone Firms Ltd, the largest landholder on the island. The quarry is nearing the end of its life and will be regenerated as a holiday caravan park to boost local tourism on the island. Perryfield Quarry is found towards the middle of the island and being actively open cast quarried. There are over 20 years of reserves left which is privately owned by Portland Stone Firms. Open cast quarrying provides quicker extraction of raw block dimension stone whilst maintaining its integrity. The majority of buildings in London today use Portland which has been quarried using the same methods over the last 60 years. Broadcroft Quarry is located on the eastern side of the island and is a part of the open cast quarries used for St Paul's Cathedral. Privately by Portland Stone Firms Limited there are over 20 years of reserves left and still being actively quarried. The coastal strip toward the southern tip of the island has permission to be worked by Portland Stone Firms and will provide in excess of 30 years of reserves. Permission has been granted for this to be open cast quarried. Once quarries have been worked they are then restored. The Portland Sculpture and Quarry Trust was formed in 1983 and is dedicated to preserving a knowledge and understanding of stone and the landscape from which it comes. The main non-working quarry remains Tout Quarry in which the trust is based, where a workshop is held every year. Tout Quarry has been donated to the Portland Sculpture and