You can save up to %25 in Hyatt Hotels in Istanbul.
Hyatt hotels are one of my personal favorites in Istanbul & i love their location. The rooms are spacious, the food is amazing and the service is very welcoming.
Here are the links that you can grab your discount.
Park Hyatt Istanbul - Macka Palas: In the Nişantası district w/ Bosphorus views & Turkish baths.
Grand Hyatt Istanbul: Upscale hotel near Taksim Square; 6 km from the Hagia Sophia.
Hyatt Regency Istanbul Ataköy: On the Sea of Marmara; 15 km to Topkapi Palace & Old City.
Hyatt Centric Levent Istanbul: Set in city center; 11 km to Hagia Sophia & the Grand Bazaar.
More details about the promotion
Check izkiz's blog post