<prompt> Translate the following text to SwahiliOriginally capped with a smooth layer of limestone it would have reflected sunlight like a beacon across the Nile valley.  <response>: Mwanzoni ilifunikwa kwa tabaka laini la mawe ya chokaa ambayo ingekuwa imepinga mwangaza wa jua kama taa katika bonde la Mto Nile. 