A short walk south-west from Summerhouse Hill is the highest point overlooking the moss. Warton Crag is 530 feet above sea level and here too there's evidence of early human settlement. A cave called the Dog Holes was excavated between 1909 and 1913 by the Manchester Museum curator J. W. Jackson. His work showed that it had been lived in from Neolithic times, through the Iron Age to Roman times. Jackson unearthed human and animal bones as well as Roman and pre-Roman pottery fragments and jewellery. He also discovered lumps of iron slag which suggested that early residents may have been smelting iron ore that had been mined locally.
Leighton Moss Ice Age To Present Day by Andy Denwood (Published 2014)
From the road you can see to the left of the gate a circular depression in the ground, and there are others in the allotment. These are considered to be pre-historic pit dwellings; also a good many rock cavities all over the Crag could easily have been converted into rude habitations. In a part consisting of waterworn limestone, deeply fissured and scored all over, there is an underground passage known as the Dog Holes Cave. In the fissures are many ferns and small trees and bushes; there isa large ash tree just at the entrance to the cave.
The Dog Holes Cave.
It is only three years since the cave was scientifically explored by Mr. J. W. Jackson, the assistant keeper of Manchester Museu. The entrance is by way of a vertical shaft due to the falling in of the roof; it is boarded up and padlocked for safety, it is is thirteen feet to the bottom of the shaft and the total length of the cave is seventy feet.
At the first exploration animal remains of the dog, sheep, goat, Celtic shorthorn, and, in less abundance, the horse, red deer, roe deer, and fallow deer were found. Also human remains of at least eleven individuals were discovered. The teeth only of the urus, the reindeer, adn the Irish elk were found. There were some metal objects including a small Celtic bronze, and red fragments of early first century pottery pointed to an earlier occupation of the cave than the period of the withdrawal of the Roman army from this country.