Recognised as a Site of Special Scientific Interest (SSSI) by Natural England, Hobbs holds international importance for preserving a unique reef formation from the Silurian Period. It's part of an abandoned quarry, stretching one kilometer north-south along the ridge east of Longhope village, Gloucester. The site features exposed bioherms and fossil-rich carbonate rocks known as Wenlock Limestone. Its accessibility makes it an ideal resource for educational groups of all ages and academic backgrounds.

Lime quarrying was an important industry in the area. Depicted on the OS map of 1889, this abandoned site was once a hive of industry activity and was quarried for lime from the seventeenth century to the end of the nineteenth century. The limestone would have been typically extracted from the quarry face through a process of drilling, blasting, and cutting the stone from the rock face with various equipment. A lime kiln was constructed at the site to process the lime.

The lime kiln at Hobbs is now in ruins, however, it was an essential part of the quarrying process and built to burn the extracted lime. The simplest method of producing lime was by using a ‘clamp kiln’. Layers of fuel and limestone were stacked together in a mound, covered with clay or turf and slowly burned in a method similar to that used in charcoal burning. The remains of the kilns at Hobbs comprises a hearth on the floor of a pit, measuring approximately up to 2.5 m in diameter and up to 2 m in depth. The surrounding soil and debris shows evidence of burning by a change in colour and loose piles of rock. The volunteers are hoping to restore the kiln in the future.

Hobbs is listed in the 'Forest of Dean Local Plan Review' as a Key Wildlife Site (KWS). Hobbs Quarry, Longhope (grid reference SO695195) is a 1-hectare (2.5-acre) geological and biological Site of Special Scientific Interest in Gloucestershire, England, notified in 1966. Doormice, a protected species, live in the reserve and are actively monitored and provided with nest boxes. Regular active conservation by volunteers is combined with research work on the geological exposures and preservation of the valuable natural environment.

The lush habitat in the reserve is great for common dormice as well as birds such as the black cap, treecreeper, great spotted woodpecker, nuthatch, buzzard and long-tailed tit.  The sheltered site is also ideal for butterflies. The Forest of Dean and Wye Valley is home to over thirty different species of butterfly. The large oaks can support up to 300 different insects and old hollow branches are nest sites to tawny owls and woodpeckers who thrive on the large insect population.

The quarry floor and walls have become colonised by common species such as ash, bramble and wild clematis. The damp walls support moss and hart's-tongue fern and moisture loving fungi. The presence of small-leaved lime indicates that the quarry was once part of an adjoining ancient woodland. Traditionally the limes were coppiced. The area supports ancient woodland flowers such as wood anemone, wood sorrel, primrose, sweet woodruff, greater butterfly-orchid, herb paris and bluebell.