On your Istanbul cruise, be sure to take time to visit Topkapi Palace. There's a lot to see on this palatial estate, and you may want to set aside a good 2-3 hours to take in the grandeur.

This was the home of the Turkish Sultan during the Ottoman Empire. It was the Sultan's primary residence from 1465 to 1853. In 1985, it became a UNESCO World Heritage Site.

Among other things, Topkapi Palace was famous for its Harem, home of the Sultan's concubines. Admission to the Harem is a separate charge, but it's well worth it....