A shuttle service from istanbul or Sabiha  airport to hotel is available  and 60 eu extra fees till 4 person per way and times. 

Hotel Sapphire is located in the old city center of Istanbul in Sirkeci. It's in walking distance to major historical attractions:

Topkapı Palace - Hagia Sophia Museum - Blue Mosque - Grand Bazaar -Spice Bazaar - Basilica Cistern - Maiden's Tower - Gülhane Park