As far as scavenger hunts are concerned, Istanbul is excellent!
The Sultanahmet / Old City area contains many impressive sites such as the Hagia Sofia and the Blue Mosque.
The Galata is also a great place for a scavenger hunt and includes Taksim Square and Istiklal Street.
All perfect for scavenger hunts. Are you having an event in Istanbul? Add on The Great Istanbul Scavenger Hunt and it will be an event to remember!