Pamukkale, meaning "cotton castle" in Turkish, is a natural site in Denizli Province in southwestern Turkey. The city contains hot springs and travertines, terraces of carbonate minerals left by the flowing water. It is located in Turkey's Inner Aegean region, in the River Menderes valley, which has a temperate climate for most of the year. The ancient Greco-Roman and Byzantine city of Hierapolis was built on top of the white "castle" which is in total about 2,700 metres long, 600 m wide and 160 m high. It can be seen from the hills on the opposite side of the valley in the town of Denizli, 20 km away. Tourism is and has been a major industry. People have bathed in its pools for thousands of years. As recently as the mid-20th century, hotels were built over the ruins of Heropolis, causing considerable damage. An approach road was built from the valley over the terraces, and motor bikes were allowed to go up and down the slopes. When the area was declared a UNESCO World Heritage Site , the hotels were demolished and the road removed and replaced with artificial pools. Wearing shoes in the water is prohibited to protect the deposits.
Sultan Ahmed Mosque is a historical mosque in Istanbul, the largest city in Turkey and the capital of the Ottoman Empire (from 1453 to 1923). The mosque is popularly known as the Blue Mosque for the blue tiles adorning the walls of its interior. It was built between 1609 and 1616, during the rule of Ahmed I. Like many other mosques, it also comprises a tomb of the founder, a madrasah and a hospice. While still used as a mosque, the Sultan Ahmed Mosque has also become a popular tourist attraction. 
Thanks so much Pinar!