Ayvalık is beautiful, stretching onto a peninsula and surrounded by islands, with many bays swirling in and out of its coastline. The bustling harbor town and Cunda Island across the way retain strong evidence of the Greek community that flourished here and prospered in the olive oil trade until being deported in the population exchange of 1923. Atmospheric back streets are full of crumbling old Greek houses. A long, sandy beach is just a short minibus ride away and various pleasure boats stand ready to take visitors on swimming and snorkeling excursions.
Ayvalık has some of the finest 19th-century Greek-style architecture in Turkey, and recent restoration has begun to reverse decades of neglect. Unlike typical Ottoman houses (tall, narrow, and built of wood, with an overhanging bay window), Greek buildings are stone, with classic triangular pediments above a square box. The best way to explore is to turn your back to the Aegean and wander the tiny side streets leading up the hill into the heart of the old residential quarter (try Talatpaşa Caddesi or Gümrük Caddesi). The artsy Tarlakuşu café on Cumhuriyet Caddesi has some useful maps to get you started.
Several historic churches in town have been converted into mosques. St. John's is now the Saatli Cami (Clock Mosque). St. George's is now the Çýnarlý Cami (Plane Tree Mosque). There are many mosques converted from churches in Turkey, but these are among the most striking—the elaborate style of Orthodox churches does not suit the plain minimalist style of mosques, and the unimpressive minaret erected later at the Çınarlı Mosque looks almost absurd. The pictures of the saints inside are painted over but can still be seen if you look carefully. The now-shuttered Taxiarchis Church holds a remarkable series of paintings done on fish skin depicting the life of Christ. Barbaros Caddesi on the south end of the pier will take you to Phaneromeni Church (Ayazma Kilisesi), displaying beautiful stone craftwork, and to the Hayrettin Paşa Camii, also converted from a church.
In summer, Sarımsaklı Plajı, the 10-km (6-mile) stretch of sandy beach 7 km (4½ miles) from the center of town, is popular, and easily and cheaply reached by minibuses that stop near the harbor. It's a crowded resort with a mess of concrete hotels right behind the seafront, and traffic and parking can be a problem, but the beach and sea are lovely.
Day or evening cruises to the bays and islands of Ayvalık are enjoyable, and range from party-boat trips to lower-key swimming excursions to the Patriça Nature Reserve on the far side of Cunda Island. Hucksters on the docks will try to sell you a trip as you walk by the boats, and competition makes prices very reasonable—about 30 TL for a day trip including a fish meal. Diving trips are also available at a higher cost. The tours are offered from May until the end of October.
Şeytan Sofrası ("the devil's dinner table"), a hilltop 9 km (5½ miles) from town, on a right turn on the road from Ayvalık to Sarımsaklı, is the place to get a panoramic view of the islands and the bays and enjoy a cup of tea or a snack at one of the cafés. It's particularly lovely at sunset, when minibuses make the return trip from town for about 5 TL.