39669
Over the years , the Nile gradually shifted westward , providing the site between the eastern edge of the river and the Mokattam highlands on which the city now stands .
 Nile, Mokattam
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Nile, Mokattam