Amwell Quarry Nature Reserve is an important wetland site in part of the Lee Valley Special Protection Area. This popular birdwatching site is a former gravel pit, now flooded, and there are regular sightings of bitterns, smews and shovelers here. Otters have recently been reintroduced into this area and may be seen either in the reserve or in the adjoining River Lee. The former Hertford East to Buntingford railway line used to run alongside the reserve from between 1863 to 1965 through the valleys of the River Ash and Rib.
