Marmara Islands (Turkish: Marmara Adaları) are an archipelago in the Sea of Marmara in the Southern Marmara Region of Turkey. Several have tourist facilities and marble quarries.

40°31′12″N 27°37′12″E

Map of Marmara Islands

The points on the map indicate each inhabited island's ferry port, which is usually the main settlement.

• 40.58727.5561 Marmara Island is the largest, with windswept hills to the north and pine forests to the south.
• 40.54727.4872 Ekinlik is the smallest inhabited island, and has no tourist facilities.
• 40.51127.4973 Avşa is the most popular, with vineyards and sandy beaches.
• 40.50927.5784 Koyun Island has a few summer houses but no permant residents and no ferry service.
• 40.46227.6265 Paşalimani is low-lying and rural, with several villages along its convoluted coast.
• Kapıdağ was the island that quit this archipelago some 2000 years ago. It became attached to the mainland and is now a lozenge-shaped peninsula; see Erdek.

A series of great geological fault lines traverse this region and are still active. Further south they threw up the mountain chain along the mainland coast, where geothermal hot springs gush from the slopes. The North Anatolian Fault pulled apart the earth's crust 2.5 million years ago to create a basin which flooded to become the Sea of Marmara; in recent times its tremors devastated cities such as Iznik. Mountains born of its ructions are now a group of islands in that sea. The limestone bedrock became seared into marble, in Greek "marmara" and long-prized as building and decorative material. And thus were named the sea and Marmara Islands. The sea was also called Propontis, "fore sea", meaning the one you cross before reaching the Black Sea. The largest island became connected to the mainland and is now the peninsula of Kapıdağ.

The islands (like other places round the Marmara coast) attracted sea-borne Hellenistic settlers, but they were never on the principal trade routes or had major cities, so their antiquities are scanty. Life here was a matter of quarrying marble, Mediterranean small-scale farming such as olive groves, but best of all tourism, which started in the Roman period. Modern tourism is entirely domestic, as the islands are close to Istanbul, and Western hotel chains and tour companies don't feature. Development has been deliberately concentrated on Avşa, which is crowded and raucous in summer. Marmara Island also has tourist facilities. Paşalimani and Ekinlik get day-trippers but are very quiet places once the afternoon ferry takes away the visitors.

There are no airports, so you take the ferry, usually from Erdek, possibly from Istanbul or Tekirdağ.

40.39527.7911 Erdek is the nearest mainland ferry port. A car ferry makes two or three circuits a day of Paşalimanı, Avşa and Marmara Island.

The direct summer foot-passenger ferry from Istanbul isn't sailing in 2022. Sail instead to Bandırma and get the bus to Erdek.

The car ferry from Tekirdağ usually bypasses the islands and sails non-stop to Erdek, but some sailings call at Marmara Island.

The main ferry is based at Avşa and makes 2 or 3 daily circuits of the other islands and the mainland port Erdek. So you can get between the islands, and a day-trip is possible from Avşa to Marmara, Paşalimanı and two days a week to Ekinlik.

Marmara and Avşa have dolmuşes and taxis waiting at their ferry ports. Ekinlik is small enough to walk, but bring a bicycle to sleepy Paşalimanı.

• The Roman quarries on Marmara Island are full of unfinished work. Indeed it was usually only rough-hewn here, to be shipped out and finished at its intended destination.
• Greek heritage: all the islands had large Greek populations until the 1923 population exchanges, so there are old houses and other buildings in variable states of repair. A good example is Asmalı on Marmara Island.

• Beaches and watersports are best found on Avşa.
• Cycle round quiet coves for views of the other islands and the sunset.
• Hills are mostly low and easy hiking, except on Marmara Island where they're more rugged, and you need to stay clear of quarry workings.

• Avşa town has a slew of places along the shore, mostly serving fish.
• On Marmara Island, Marmara town has the main strip, but there's eateries in the other villages.

• Most bars are within hotels or restaurants, there aren't free-standing pubs.
• Wine is made on Marmara Island. There are no vineyards you can tour, but ask around for the local product.

Usual precautions about traffic, safeguarding valuables, sun protection, and water safety - beware drunken idiots on jet-skis, and don't be one of them.

The ferry returns you to the mainland at either Erdek, Istanbul or Tekirdağ.