Belgrad Forest

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.

It has a sandy beach backed by forest where a creek runs out. This is as far as you can go in a standard car.

An attractive stairway mixing the Neo-Baroque and early Art Nouveau styles, climbing up from Bankalar St towards the Galata Tower. It was built in the 1870s by Abraham Salomon Camondo, who belonged to a prominent Ottoman-Venetian Jewish family of financiers and philanthropists.

The third and grandest of the churches on this site, completed in 537 AD. The 30-m diameter dome covers what was for over 1000 years the largest enclosed space in the world, only surpassed in 1520 by Seville cathedral. It used "pendentive" architecture to throw the dome's weight onto four stout pillars, a design that inspired many Eastern Orthodox churches and Ottoman mosques. It became a mosque after the Ottoman conquest in 1453, remaining so until 1931. It was then a museum until 2020 when it was again proclaimed a mosque. That means you must work around prayer times and dress appropriately.

The only active Ashkenazi Synagogue open to visits and prayers.

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.

The Church of Theotokos Pammakaristos ("All-Blessed Mother of God") was built between the 11th and 12th centuries. The parekklesion or side-chapel was added maybe 1300, with rich mosaics. The main building became a mosque in 1591, named for Sultan Murad III's conquest (fetih, hence Fethiye) of Georgia and Azerbaijan: the interior was opened up, but the chapel was undisturbed and in modern times became a museum. In 2020 the entire building was proclaimed a mosque, and every scrap of Byzantine artistry was covered up, so now there's nothing worth seeing.

A Byzantine monastery complex carved into a cliff, set in a lush valley. The site is free, but May-Sept there's a 32 TL toll for cars on the access roads. There's a picnic area, pity about all the trash, and a couple of restaurants nearby.

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.

Started in 1613 by the Ottoman sultan Ahmet I (r. 1603–1617, who also had the Blue Mosque in the Old City built), and extensively renovated by the art-loving Selim III (r. 1789–1807), this sole building, which itself has the distinction of being the only intact structure that dates back to the rule of Ahmet III (r. 1703–1730), set inside a beautiful garden of pools and mature cedar and magnolia trees is the only remaining part of what was once the fourth largest palatial complex in Istanbul, extending all the way to the banks of the Golden Horn (which is now occupied by the derelict buildings of the closed shipyard, which also block part of the view towards the shore). According to the local rumour, its name (which in Turkish means "mirrored poplar") derives from the now absent mirrors gifted by Venice to the palace that were presumably "as tall as the poplars" (aynalar kavak). The highly decorative and colourful interior includes several rooms of original furnitures fit for a sultan, some of which are covered with nacre, and walls embellished with Ottoman poems praising the palace and Selim III. Downstairs is a small museum dedicated to music, which exhibit some of the instruments (violins, ouds, and kamanchehs) and gramophone records owned by Fatma Gevheri Sultana (1904–1980), the granddaughter of Abdülaziz I (r. 1861–1876). While you are outside, also check out the old main entrance (now closed) towards the Golden Horn, topped by a dome. Worth the half hour spent there.

If you are already in the area, it's worth considering to visit this waterside neo-Baroque manor, built in the 19th century for the countryside and hunting excursions of the Ottoman dynasty. The area, where the Göksu River flows into the Bosphorus, was known as "the Sweet Waters of Asia" by the pioneer European travellers of the epoch (as opposed to "the Sweet Waters of Europe", another contemporary elite recreational area on the other side of the city, where the Kağıthane and Alibeyköy Rivers empty into the Golden Horn).

Built circa 1200 as the Eastern Orthodox Theotokos Kyriotissa Church, after the Ottoman conquest it was handed over to the Qalandari, a Sufi sect. In the mid-18th century it was converted to a Sunni mosque, and its mosaics were plastered over. The original appearance was restored in the 1970s.

This is a completely wooden building rising up to six storeys. It is said to be the second largest wooden construction in the world and the first in Europe. On the second highest summit of Büyükada (İsatepe, "Jesus hill", 164 m asl), it lies abandoned and dilapidated amidst the pine woods, like a picture-perfect haunted manor. It was built in the late 19th century, originally intended as a luxury hotel for the passengers of the Orient Express but never served that purpose and was put in use as an orphanage by the Greek community until it was closed down in 1964, within the context of the deteriorating Turkish-Greek relations due to the Cyprus dispute. It's dangerous, not to say forbidden, to enter the building due to the damages inflicted by decades of neglect. The title holder is the Ecumenical Patriarchate, led by Bartholomew I who wants the building restored and made a global environmental research centre (he's known as the "Green Pope" due to his efforts for environmental protection), but given the long legal disputes on titleship, not to mention the enormous funds required to bring the building to life, don't hold your breath.

The Byzantines built several great palaces in Constantinople and this is the only one to survive almost intact. It's from the late 13th century, in typical alternating marble and red-brick rows, and was an imperial residence: Porphyrogenitus means "born to the purple" indicating the heir to the crown. Yet it was merely an annex or pavilion within the much greater Palace of Blachernae, of which nothing else remains. It's set within the north end of the Theodosian Walls and was much bashed during the Ottoman capture. Later it was variously a menagerie, brothel, pottery, poorhouse and bottle works, then fell derelict in the 20th century. In 2021 it re-opened as a museum.

This building dating back to 1945 houses the local radio branch of the state radio and television corporation of Turkey (TRT). Not exactly an architectural pearl (although fans of the 1940s' totalitarian architecture will likely find its stately façade interesting), but it is prominent for the part it played in the political history of Turkey: It was occupied three times by the Army, in 1960, 1971, and most recently in 1980, when the radio was decidedly the broadcast type ranging most wide and far, to announce that they had launched a coup and taken over the governance of the country.

This was rediscovered in 2010 when an overlying building was demolished. It was built circa 430 AD to store water brought in by Valens Aqueduct. It's smaller than the better-known Basilica Cistern, but better lit, more atmospheric and less touristy.

A profusion of carpets, rugs, calligraphy, pottery, Qu'rans and other manuscripts. The museum is housed in the Palace of Pargalı Ibrahim Pasha (1495–1536), who was grand vizier to Suleiman the Magnificent, and the best of pals till Suleiman had him murdered.

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.