I had a great time staying in Gizem's apartment in Beşiktaş. The view from the balcony is amazing :) During my whole stay Gizem was very supportive and answered messages immediately. Beşiktaş bar district, Ortaköy and the ferries to anatolian side are within walking distance. The house itself is quite old but will be renovated soon. Since the area is hilly and the demand for taxi drivers is high in Istanbul it's a bit tricky to find a taxi sometimes.