Kilyos

Kilyos, on the shore of the Black Sea, is the closest seaside resort to Istanbul and very popular. It has a long, sandy beach and temptingly clear water, but visitors should not swim here in the absence of a lifeguard because there are dangerous currents beneath the calm surface.
A 14th-century Genoese castle perches on a cliff top overlooking the town but it is not open to visitors. The three ruined towers on the left of the main approach road into the village were formerly water control towers. They were part of the system that once brought water here from the Belgrade Forest.

Sile

The quintessential Black Sea holiday village of Şile has a number of fine, sandy beaches and a black-and-white striped cliff-top light-house. In antiquity, the village, then known as Kalpe, was a port used by ships sailing east from the Bosphorus.
Şile's lighthouse, the largest in Turkey, was built by the French for Sultan Abdul Aziz in 1858-9; it can be visited after dusk. Apart from tourism, the main industry is now the production of a coarse cotton which is made into clothing and sold in shops along Üsküdar Caddesi.

Polonezkoy

Polonezköy was originally called Adampol, after the Polish Prince Adam Czartoryski who bought prime arable land here in 1842 for Polish emigrants settling in Turkey. Soon after, in 1853, the Poles formed a band of Cossack soldiers to fight for Abdül Mecit I  in the Crimea. After this he granted them the land as a tax-free haven.
Polonezköy's rustic charm is now big business, and a number of health spas and villas have sprung up. A couple of restaurants still serve the pork for which the town was once famous.
The surrounding beech forest, which offers pleasant walks, has now been protected from further development. As part of this scheme, the locals have even waived their rights to collect firewood. (s1)