Büyükdere Avenue Büyükdere Avenue Büyükdere Avenue () is a major avenue which runs through the districts of Şişli (Esentepe quarter), Beşiktaş (Levent quarter) and Sarıyer (Maslak quarter) on the European side of Istanbul, Turkey. It begins at Şişli Mosque and runs in an eastward direction partly under the viaduct of the inner-city motorway O-1 through Mecidiyeköy, Esentepe, until reaching Zincirlikuyu; where it joins with Barbaros Boulevard and turns northward passing through Levent, Sanayi Mahallesi, Maslak and by the Fatih Forest, ending at the Hacıosman Slope on the Sarıyer district border. Its total length is . From Zincirlikuyu to Maslak, it forms a
Ionia Downtown Commercial Historic District the city, serving travelers arriving by railroad. Much of the building stock in the district was built starting around this time, as Ionia grew in the late ninetheenth century. The Ionia Downtown Commercial Historic District covers nearly all of Ionia's central business district, and includes buildings which were constructed primarily in the late nineteenth and early twentieth centuries. Eighty-five structures are included in the district, of which seventy contribute to the historic nature of the district. These buildings are primarily commercial, although the district does include some residential, religious, and governmental buildings. The commercial blocks stand side-by-side, directly on the