Sentence:  At the beginning of the Hippodrome I saw the Kaiser 's Fountain , an ugly octagonal building with a glass dome , built in 1895 by the German Emperor , and on my left , directly across from it , the tomb of Sultan Ahmet , who <WSD>constructed</WSD> the Blue Mosque , more properly known by his name . 
Meaning of the word marked with <WSD> tags:  make by combining materials and parts