In the early 1930s, at the suggestion of C. F. C. Hawkes, Varley turned his attention to the hillforts of Cheshire. His excavation of Maiden Castle on Bickerton Hill was his first on a hillfort, and the first to be carried out by an archaeologist on any hillfort in the county. He started to excavate in 1932, aided by a group of his students from the University of Liverpool, but the main excavations of 1934 and 1935, supervised by Varley with J. P. Droop, were carried out under the Bickerton Camp Scheme, which recruited an assortment of volunteers including unemployed Liverpudlians, school children and members of the Liverpool Ramblers' Association. The investigation concentrated on the hillfort's inturned entrance, where post-holes were found, suggested to be gateposts. Trenches were also cut through the double ramparts. The inner ramparts were found to consist of sand and carbonised oak timbers protected by a stone cap and revetments (retaining walls), which Varley compared with the murus gallicus method of construction, typical of Gaul. An outer revetment protected the outer ramparts, which had an internal line of turf, suggesting the possibility of multiple phases of construction. Varley described Maiden Castle as a promontory camp; he initially concluded that it dated from around 0-50 AD and had subsequently been strengthened in around 50 AD when Roman expansion began to threaten the area. By 1940, he had revised these dates substantially earlier, concluding that the hillfort was built in the 2nd century BC and had been strengthened in the 1st century BC; modern radiocarbon dating moves the dates earlier still. A contemporary review of his 1937 paper on the excavation describes it as a valuable review of the problems of the life of Britain in the few centuries before the Roman conquest. Modern archaeologists Richard Mason and Rachel Pope describe his reports on Maiden Castle as showing fairly meticulous archaeological reasoning.