Belgrad Forest

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.

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 avenue has little in common with Baghdad, except it was the beginning of the Ottoman-era route to that city followed by many, including Ottoman sultan Murat IV during his march upon Persia, after which he captured Baghdad. In fact, with its sidewalk cafés and Western restaurants, Bağdat Caddesi is usually considered as one of Istanbul's most western-flavoured streets, ironically located in Asia. This street is not completely pedestrianized unlike Istiklal Street, which serves a similar function on the European Side, but its broad sidewalks with tree shade offer a pleasant walk. The restaurants and cafés on the avenue are mainly upscale, but there are also some quite affordable ones scattered around occasionally. Shopping opportunities also abound. From Kadıköy, take the Bostancı-bound dolmuşes (from just south of the ferries) or the public bus #4 (its stop is near the one for the dolmuş, but separate).

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.

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.

A remarkable Bulgarian Orthodox church better known as Demir Kilise, "Iron Church", as it's a cast iron prefab. The Bulgarians split from the Greek Orthodox and established their own wooden church in 1870, which burned down. The ground was too weak for a masonry or concrete structure so they opted for cast iron. The sections were cast in Vienna, shipped here and assembled, to open in 1898. The church was renovated in 2018, but the archpatriarchate building across the street remains a gaunt shell.

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.

Built in first half of the 15th century, this is the large medieval castle under the Second Bosphorus Bridge. Its former name Boğazkesen (Turkish)/Laimokopia (Greek) means both "strait-blocker" and "throat-cutter" in both languages and denotes the reason of its building—to shut the supply routes from the Black Sea in the north into the slowly falling apart Byzantine Empire through the Bosphorus. Rumeli, literally "the Roman land", was the name of the European half of the Ottoman Empire, and as is usual with some other structures and villages along the Bosphorus, used as a prefix to differentiate Rumeli Hisarı from its counterpart in the Asian Side, the much smaller Anadolu Hisarı just across the Bosphorus.

Stretching west from the park is this impressive 16th-century stone bridge with four humps and 28 arches spanning the channel between lagoon and sea. The bridge is pedestrian only and offers some very nice views, so it's worth walking across the entire (breezy!) span via the three islets to the quiet western end, even though beyond is industrial gap site, with the modern highway roaring to the south. In the park, the pillbox menacing the bridge was part of the "Çakmak Line", the World War II fortifications stretching from here to Terkos, which were Istanbul's last line of defence from the west. The pillbox exterior is colourfully decorated but the interior is closed.

Dedicated to toys, this is a museum which adults can enjoy as much as kids. It's founded by poet Sunay Akın, and is housed in a historical mansion in the Göztepe neighbourhood east of Kadıköy. Among the 2,000 pieces of toys from around the world in exhibition, the oldest are a French-made violin from 1817 and a U.S.-made doll from 1820.

A contemporary art museum in a building converted from an old power plant: 1914-built and coal-fired, this was the oldest in Istanbul and the Ottoman Empire. Part of the plant was kept in almost exact original condition and now serves as the "Energy Museum".

This attractive neighbourhood was home to a large Christian and Jewish population until some decades ago and still has a number of sights like two synagogues, some churches among which the Armenian Surp Krikor Lusavoriç, dozens of wooden houses and a Jewish and Christian cemetery.

The only active Ashkenazi Synagogue open to visits and prayers.

A medieval citadel on the Bosphorus at the mouth of the Göksu creek. It was built in the late 14th century to control (polite word for "choke off") shipping along the Bosphorus, which narrows to 660 m at this point. It worked in tandem with Rumeli Citadel, built some 50 years later on the European bank. It fell into disrepair but was restored in the 1990s. You can't go in, but it's a pleasant setting; the entire village is named Anadolu Hisarı after the fort and has many traditional wooden houses (yalı). Ferries along the Bosphorus call here.

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.

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.

The imperial enclave of the Ottoman emperors for four centuries. Lavishly decorated, with exhibitions of fine craftmanship and four courts of increasing grandeur. The second court has the Harem and the State Treasury, housing a weaponry display. The third court has the Imperial Treasury, with Islamic and Christian relics. The views from the Fourth Court over the Bosphorus are spectacular. Reckon on spending several hours here and bring water as the museum kiosk is overpriced.

A neighbourhood east of Şişli known for its Art Nouveau apartment buildings, the ground floors of many of which are upmarket restaurants, cafes, pubs, and garment stores lining the sidewalks. Nobel laureate Orhan Pamuk, well-known Turkish novelist, is a lifelong resident of the neighbourhood which formed the background of several of his novels.

A private museum with a large painting collection and archaeological collections of measurement units and tools used in Asia Minor since antiquity and faiences of Kütahya.

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.