Archaeologous is highly recommending that when you are in Istanbul you make sure to see the Blue Mosque. We usually include a visit to both the Blue Mosque and the Hagia Sosphia which is across the park from the Blue Mosque on our 'favorites of Istanbul tours.
You will perhaps understand why you should see the Blue Mosque after a few interesting facts. Building was originally started for the young Sultan Ahmet I in 1609. He ascended the throne when he was only 13 and died at 27, only one year after the Mosque was finished. It took 8 years to complete the mosque and the rest of the area two years later. It was a whole village complex with a bazaar whose collected rents went to supporting the mosque (the mother of the sultans idea) a hamam for the faithful to bathe on the holy day, Friday, a public fountain, a hospital, soup kitchen, primary cook, shops of tradesmen, and the sultan's chambers. You can see some of these still today.
When you walk up to this active mosque, you might think you are in the wrong place. Not to worry, the "inside" is where the 'Blue' Mosque gets it's name. You see the inside is covered with 20,00 blue glazed Iznik tiles. The outside is undeniable with its six minarets 15' wide and 129' in height, which makes it 5 stories high. You will hear the call to prayer six times a day. Please no photos of anyone praying and for you ladies make sure you wear a scarf over your head and shoulders out of respect..