Istanbul's Asian coast, lined with wooden yali (waterside mansions where wealthy Turks spend their summers), has charming little neighborhoods, including bustling Çengelköy, now the site of one of the city's most luxurious boutique hotels. Meticulously created from a former factory that manufactured raki—the local anise-flavored drink.—the Sumahan sits near the soaring Bosphorus Bridge, at the edge of the water. Its 18 modernist, high-tech rooms overlook the twinkling lights of the European side. Lower-floor rooms have French doors that open onto a shared lawn. The reservations-only restaurant, Kordon, serves world-class Turkish cuisine. (Caveat: Seafood from the overfished Mediterranean is expensive, and a full dinner can run well over $100 a head.) A hotel boat is available to ferry visitors to places of interest along the Bosphorus.
When to go: April, May, June, September, and October, to avoid the summer crowds and humidity.
Which room to book: Executive Suites, for their marble bathrooms and exquisite views (doubles, $220).