Since I visit Istanbul twice a year, I have experienced many 4 or 5 star hotels in this city. Believe it or not, you will find many hotels with a 5-star rating on travel websites, but these hotels are actually rated 3 stars. So do not pay attention to those stars. The most important thing is cleanliness, maintenance and hospitality, which I think you will find at Gallery Residence & Hotel.
Nişantaşı is a residential quarter in the Şişli district on the European side of Istanbul and is known for its unique shopping selection. It is easy to feel a luxurious atmosphere in the streets. For both locals and tourists, Nişantaşı is the place where fashion lives and grows. The hotel is located in a quiet street, 5 minutes walk from Abdi İpekçi. Nearby is a new shopping center (Lotus), from which you can easily reach Osmanbay Street and the metro station.
If you are interested in visiting beautiful old French designed buildings and warm atmosphere, you can walk 20 minutes to Istiklal Street. There is a pub (Meyhane) and a good grocery store in front of the hotel, but the area was very quiet at night. During the day, this street is very lively and busy because of the many tailor and barber stores.
As for the decoration of the hotel, you feel like you are in an art gallery, so the name is so perfect for this place. Your eyes will be fed by the many posters and paintings and the rooms inscribed with famous painters. I was in the Lautrec (the French painter) room.
Would fully recommend.