the earliest evidence of habitation in the ilkley area is from flint arrowheads or microliths, dating to the mesolithic period, from about 11,000 bc onwards. the area around ilkley has been continuously settled since at least the early bronze age, around 1800 bc; more than 250 cup and ring marks, and a curved swastika carving dating to the period have been found on rock outcrops, and archaeological remains of dwellings are found on ilkley moor. a druidical stone circle, the twelve apostles stone circle, was constructed 2,000 years ago. serious interest in the rock art of ilkley began after the publication in 1879 of the "prehistoric rock sculptures of ilkley" by romilly allen in the "journal of the british archaeological association".