have the Northumbrian dialect recognised as a separate language. It is possible that traces of now-extinct Brythonic Celtic languages from the region survive in some rural areas in the Yan Tan Tethera counting systems traditionally used by shepherds. Contact between English and immigrant languages has given rise to new accents and dialects. For instance, the variety of English spoken by Poles in Manchester is distinct both from typical Polish-accented English and from Mancunian. At a local level, the diversity of immigrant communities means that some languages that are extremely rare in the country as a whole have strongholds in Northern towns: Bradford for instance has the largest proportion of Pashto speakers, while Manchester has most Cantonese speakers. History The prehistoric North During the ice ages, Northern England was buried under ice sheets, and little evidence remains of habitation – either because the climate made the area uninhabitable, or because glaciation destroyed most evidence of human activity. The northernmost cave art in Europe is found at Creswell Crags in northern Derbyshire, near modern-day Sheffield, which shows signs of Neanderthal inhabitation 50 to 60 thousand years ago, and of a more modern occupation known as the Creswellian culture around 12,000 years ago. Kirkwell Cave in Lower Allithwaite, Cumbria shows signs of the Federmesser culture of the Paleolithic, and was inhabited some time between 13,400 and 12,800 years ago. Significant settlement appears to have begun in the Mesolithic era, with Star Carr in North Yorkshire generally considered the most significant monument of this era. The Star Carr site includes Britain's oldest known house, from around 9000 BC, and the earliest evidence of carpentry in the form of a carved tree trunk from 11000 BC. The Lincolnshire and Yorkshire Wolds around the Humber Estuary were settled and farmed in the Bronze Age, and the Ferriby Boats – one of the best-preserved finds of the era – were discovered near Hull in 1937. In the more mountainous regions of the Peak District, hillforts were the main Bronze Age settlement and the locals were most likely pastoralists raising livestock. Iron Age and the Romans Roman histories name the Celtic tribe that occupied the majority of Northern England as the Brigantes, likely meaning "Highlanders". Whether the Brigantes were a unified group or a looser federation of tribes around the Pennines is debated, but the name appears to have been adopted by the inhabitants of the region, which