Due to the limited amount of time that we had in Istanbul, we opted to see the Sulemaniye Mosque instead of the Blue Mosque during our tour of the city. It's away from a lot of the other major sites in Istanbul, but I would highly recommend it. It's very much worth the visit. The mosque is an architectural marvel. There were so many amazing details used in the design of the mosque, down to the use of ostrich eggs to ward away spiders. It's also absolutely beautiful.