Before the building of the Aswan Dam, the River Nile was home to many thousands of crocodiles, and some would gather on the muddy banks here to sun themselves.
Prior to the Aswan Dam's construction, there were many crocodiles residing in the River Nile. 
mnli hypothesis: Prior to the Aswan Dam's construction, there were many crocodiles residing in the River Nile.  premise: Before the building of the Aswan Dam, the River Nile was home to many thousands of crocodiles, and some would gather on the muddy banks here to sun themselves.