Istanbul
Sultanahmet
Basilica Cistern (Yerebatan Sarayi) - The Basilica Cistern is a "must see" - an underground water system from 532 AD, built by the Byzantine emperor Justinian. The cistern stored millions of gallons of water, brought from outside the city by an aqueduct. It was so well constructed, the cistern was used by the palace (including the Ottomans) for centuries. Walk through a maze of massive columns, reflected in clear pools of water (there are wooden boardwalks so you won't get your feet wet). Don't miss the two huge stone heads of Medusa, one she's upside down (doing a headstand?), the other her head is sideways. After you've toured the cistern, stop into the cafe for drinks and snacks, it's nice and cool in the cistern on a hot day.
Aya Sofya (Hagia Sophia) - Aya Sofya, Church of the Holy Wisdom, completed by Justinian in 537 AD, was the most celebrated building in Christian Byzantium. The interior of its huge dome, 184 ft high (taller than the Parthenon), was covered with glittering mosaics. In 1204, Crusaders looted the gold and silver icons from the church. When Constantinople fell to the Ottoman Turks, Aya Sofya became a mosque, and four minarets were added. Today, this magnificent building is a museum (closed on Mondays).
When you step into the nave, it's amazing to stand under the dome and look up - windows around the bottom of the dome let in light, and the dome floats in the heavens. On eight wooden plaques are inscribed in Arabic the names of Allah, the Prophet Mohammed, four caliphs and two of the Prophet's grandsons; on the inside of the dome are words from the Koran.
Throughout Aya Sophya, over the entrance, in the apse and upper galleries, are incomparable mosaics. Kids can appreciate different mosaics of the Virgin Mary, holding the baby Jesus on her lap. The Virgin is also accompanied by the Byzantine emperors Constantine and Justinian in one mosaic, by emperor John II Comnenus and his empress Irene in another. The most majestic mosaic is the 13th century Deesis, with Christ Pantocrator ("all-powerful"), the Virgin Mary, and John the Baptist.
Blue Mosque (Sultanahmet Camii) - The Blue Mosque was the imperial mosque of Sultan Ahmed, built in 1616. It has six minarets, with a large courtyard, multiple domes, porticos, and honeycombed archways. The Blue Mosque is still in use, so when you go in, you'll take off your shoes, and head coverings are available for women.
It's quite a contrast to step from the bright courtyard into a blue world - the interior of the mosque is exquisitely decorated with tiles in arabesque patterns. In the lower sections, look for the famous Iznik tiles with four different flowers, tulips, roses, carnations and lilies, in turquoise, red, white and green.
Mosaic Museum - It's well worth a visit to the Mosaic Museum, originally a section of the Great Palace of the Byzantine emperors. The exquisite mosaics, situated as they were in the palace, show scenes of daily life and cultural traditions around 5th - 6th century AD. In the mosaics, two youths fight a tiger, a women carries a pot on her head, a stubborn donkey refuses to eat, a winged creature flies through the air, clutching a snake in its claws.