Cistern of Philoxenos
Time Out says
Dating back to the 5th century, the Cistern of Philoxenos is one of Istanbul’s surviving Byzantine subterranean reservoirs and a hidden gem that’s off the tourist trail. While its Turkish name, Binbirdirek Sarnıcı, translates into ‘1001 Columns’, the number isn’t used literally here but as a turn of phrase denoting multitude. The cistern is actually built on 224 columns standing more than 10 meters tall, most of which are engraved with a Greek mason’s mark. In recent years, the cistern has hosted a variety of events including concerts, fashion shows and exhibitions.