Although we may have seen the top three sights of Istanbul on our first full day of sightseeing, we couldn't leave Sultanahmet without visiting the Basilica Cistern. We just had to. It was in the area and it is an important and historic site as well. Not included in our Museum Card, we had to pay the admission fee to enter but it wasn't much. I can no longer recall exactly how long we stayed here but I figured we spent a good 30 minutes to an hour here. On this visit, we just couldn't miss the upside down head of Medusa.