27492
Prehistory The earliest evidence of habitation in the Ilkley area is flint arrowheads or microliths , dating to the Mesolithic period , from about 11,000 BC onwards .
 Ilkley
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Ilkley