Hertfordshire Geological Society (HGS) is a local organisation for anyone interested in geology, from beginners to experienced enthusiasts and professionals. Established in 1975, the Society became independent in 2003 and is a Local Group of the Geologists’ Association. Its activities include monthly talks, field trips and geoconservation work, offering members opportunities to learn about geology and explore it in the field.

HGS shares information about Hertfordshire’s geological heritage through resources on local solid formations, superficial deposits, chalk streams, puddingstone and building stones. Its website also features an interactive map, videos, trails, information boards, church guides, learning materials and places to visit. The Society supports geoconservation through information about sites, including RIGS and SSSIs, and highlights work by related groups and organisations.

To mark its 50th anniversary in 2025, HGS is preparing a book featuring 50 illustrated geological sites and objects that tell the story of Hertfordshire’s geological past. The Society welcomes people of all ages and experience levels to join its activities and discover the county’s geology.