Haydarpaşa railway station

A village with an impressive citadel overlooking the Bosphorus and its mouth into the Black Sea. By land it's accessible only by a hairpinning road through the forest, with few buses. It's best reached by ferry from Eminönü (twice daily) or Sariyer (frequent). In the village, a road is signposted up to the hilltop Yoros citadel (a little more than 1 km, 20 min on foot, free admission). There's a pleasant area with cafés by the ferry pier; the place gets crowded at weekends during summer. Nasty big dogs stalk the citadel area at night. See Istanbul#The_classic_Bosphorus_cruise.

The defining image of Istanbul, dominating the skyline with its great dome and six minarets. Completed in 1617 for Sultan Ahmed I, it's still a working mosque, so dress appropriately and avoid prayer times. Enter via the courtyard on the SW side. You step (shoeless) into the blue-tiled prayer hall beneath the main dome and its semi-domes. The mihrab is of finely carved marble, well-lit, and the minbar (pulpit) next to it is visible from almost all parts.

Sokollu Mehmet Pasha was the grand vizier and de facto ruler of the Ottoman Empire during its 16th century golden age. He commissioned this mosque, one of three in the city to bear his name, but the sloping site was a challenge. He hired the best, Mimar Sinan, who completed it in 979 AH / 1571 AD, with the slope resolved by a fronting courtyard above shops and a medrese. The interior has outstanding İznik blue tiles, and three fragments of the Black Stone (Hajar al-Aswad) of the Kaaba: above the main entrance, minbar and mihrab.

Completed in 1851, this houses a mantle said to have been worn by the prophet Muhammad. The mantle is displayed during Ramadan.

On top of a hill overlooking the Golden Horn, this is a magnificent mosque built by Sinan in the 1550s. It was centrepiece of a large külliye, a religious complex which included madrasas, a public kitchen and a hospital.. The small cemetery east has the mausoleums of Suleiman the Magnificent and of his wife Hurrem Sultan or Roxelana.

A military-based museum with various warplanes, helicopters, and weapons used by Turkish Air Force, and also civilian air transport and examples of Turkish aeronautics from Ottoman era onward.

A resort on the Marmara coast. It's the westernmost part of Istanbul, between Çatalca and the province of Tekirdağ. There are some remnants of the Anastasian wall here, the scrappy ruins of a castle, an ancient cistern, the Piri Paşa Mosque, and Uzunköprü the long aqueduct.

The only active Ashkenazi Synagogue open to visits and prayers.

This is an industry museum showcasing the evolution of machines. Many transport related items including a submarine, classic cars, railway carriages, an out-of-service Bosphorus ferry and a Douglas DC-3 aircraft (possible to board) are on display, among others. Also houses a typical Istanbul streetscape with its shops and all as how it would look in the past.

Although not at the size of Hagia Sophia, this is the largest active church in Turkey. It’s directly on Istiklal St, but somewhat hidden from view by its yard portal. Catholic Masses in Italian, Turkish, and English (in different days of the week).

Vast underground cistern built by Justinian in 532 to store the city's water, the largest and best-known of the hundreds constructed. It's a cathedral-like space with 336 richly decorated columns. Time was you explored in a little rowing boat, but tourist numbers have soared and water levels have dropped, so now you follow a boardwalk, with lights, piped music and art installations. It's sometimes a film location, and stages concerts. But the crowds rob it of atmosphere and you might prefer to seek out one of the less-visited cisterns.

Opened in 2012, this museum is unique and a must-see when you are in the Beyoğlu area. It was created by Turkish Nobel laureate Orhan Pamuk alongside a novel of the same name. It tells the love story of the two main characters from the novel, and represents life in Istanbul during the late 1970s to early 1980s, as it exhibits thousands of objects from that era.

The building was erected as a Roman Catholic church in 1325 by the friars of the Dominican Order, near or above an earlier chapel dedicated to Saint Paul (Italian: San Paolo) in 1233. In 1299, the Dominican Friar Guillaume Bernard de Sévérac bought a house near the church, where he established a monastery with 12 friars. A new, much larger church was built near or above the chapel of San Paolo in 1325. Thereafter the church was officially dedicated to San Domenico. After the Fall of Constantinople, according to the Capitulations of the Ottoman Empire with the Republic of Genoa, the church, which by that time was known by the Turks under the name of Mesa Domenico, remained in Genoese hands, but between 1475 and 1478 it was transformed, with minor modifications, into a mosque by the Ottoman Sultan Mehmed II and became known as Galata Camii ("Galata Mosque") or Cami-i Kebir ("Great Mosque"). Towards the end of the century Sultan Bayezid II assigned the building to those Muslims of Spain (Andalusia) who had fled the Spanish Inquisition and migrated to Istanbul; hence the present name Arap Camii (Arab Mosque). Today, Arap Camii is the largest mosque on the Galata side of the Golden Horn. It is one of the most interesting mosques in the city due to its early Italian Gothic architectural style and church belfry, which has practically remained unaltered even after being converted into a minaret.

A historic 3-storey house, easily distinguishable among the modern apartment buildings thanks to its brightly coloured and gracefully decorated exterior. This is where the future founder of the Turkish Republic, Kemal Atatürk rented in 1919 while staying in Istanbul before setting sail to Samsun on the Black Sea coast to start the Turkish War of Independence. Hosts Atatürk-related paraphernalia and photos.

Built in the early 5th century as a monastery dedicated to Saint Andrew the Apostle, in 766 it was the burial place of Saint Andrew of Crete and was later re-dedicated to him. It was rebuilt in the late 9th century and again in the 13th, then around 1490 converted into a mosque. From the 16th century it was occupied by the Dervishes, when the legend arose that a chain hung to a cypress tree in the courtyard was a truth diviner. The chain was swung between rival witnesses and the one it hit was telling the truth. The cypress stump is still standing.

A neo-gothic Anglican cathedral which would not be out of place in northwestern Europe, the Crimean Memorial Church was built for the Protestant community of the city by Britain in the late 19th century. It was named in honour of the soldiers died in the Crimean War of 1856, fought against Russia by the allied Ottoman and British Empires. The congregation of the church today mostly consists of Anglican East Asians and Sri Lankans resident in Istanbul.

One of the icons of the city is also called the Leander's Tower, on a Bosphorus islet off Salacak. The local myth ascribes its name to a princess, whose father wanted to protect her in this offshore tower from a prophecy that she would be killed by a snakebite on her birthday, but the snake found its way inside a basket of fruits — ironically a birthday present from her father — and you've probably already guessed the rest of the story. In actual timeline, it served as a defensive structure (there was a wall connecting it to the Asian mainland, and the Byzantines used to stretch a chain from here to the European mainland across the mouth of the Bosphorus to shut it to adversary shipping in times of conflict, but they didn't during the final Ottoman siege in 1453), as a customs and quarantine station, as a lighthouse, as a warehouse of various sorts of goods, and as a high-end restaurant before the last restoration finished in 2023 dedicated it as a museum. There is a light show viewable from the mainland every day at 21:00.

The Greek Orthodox church is on the highest summit of the archipelago, Yücetepe ("great hill") at 203 m asl. Walk up from Birlik Meydanı for about 35-40 min; the cobbled incline is too steep for a bicycle. The church building is unexceptional, but the backyard has a great view of the other islands and the sea. St George's day is celebrated here annually on Apr 23, when you can expect tens of thousands attendees willing to make wishes — if you want to skip the crowds set off before 06:00 or else you will be standing for a long time until you are let inside by the police in groups of 10–15 people at once. Wishmaking rituals range from usual candle burning, to slightly more unusual climbing up to the church on bare feet, to very curious untying wool balls all along the path leading there. If you are interested to partake, you will meet lots of vendors selling candles on the streets that day, right as soon as you step out of the ferry, but it's best to have them from the church for a donation. In case you are wondering if all of Turkey's dwindled Greek Orthodox minority are there that day, or if the community is even that populous, no, most of the visitors eagerly waiting for a blessing from the priest are non-Christian Turks, but there is nothing surprising about that: this is Turkey, where the east and the west meet, and cultures truly mix.

The original mosque was built between 1463-1470 by the Greek architect Atik Sinan, by order of Sultan Mehmet II the Conqueror, on the site of the former Church of the Holy Apostles, which had served as Byzantine Imperial burial place for a thousand years. The grand complex with eight medreses, a library, hospital, hospice, caravanserai, market, hamam, primary school and public soup kitchen was smashed again and again by earthquakes, and the present building is from 1771 to a different design. The interior is lavish, and outside is the ornate tomb of Mehmet II and his wife Gülbahar Hatun.

Museum in a restored building that was the stables for Topkapı Palace. It exhibits various instruments for astronomy, clocks, pumps, weaponry and so on developed in Islamic realms down the centuries, but these are modern repro, and explanations of their context are skimpy. Islamic science and technology preceded that of Europe, as they insist, but they get the tone wrong, as if that was the triumphal culmination rather than the springboard for further advance.