Built on the orders of Sultan Ahmet 1 in 1606, the Blue Mosque is a dominant landmark in the center of Istanbul.  The architect was Mehmet Aga and the Mosque took 7 years to build.  The Sultan himself joined the builders on several occasions to lend a hand, but died within 12 months of its completion.  Built in the Classic Ottoman Style, the architecture is exceptional in having six minarets.  And as the name implies, it is decorated on the interior with blue tiles and blue glass work.  It remains a living place of worship.