Çatalca

The only active Ashkenazi Synagogue open to visits and prayers.

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.

This is a 1927 Beaux Arts building named after its patron Süreyya İlmen Pasha, then a deputy of Istanbul who was impressed by theatres in Europe during his visits. It became the first opera house in the Asian side of Istanbul, but due to deficiencies in its interior design, it barely staged any opera and was converted to a cinema soon afterwards. It underwent a significant restoration and reverted to its original purpose in 2007, so now houses performances of ballet, opera, and classical music; good tickets are often extremely cheap.

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.

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).

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.

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.

Turkey was slow to protect its antiquities and to display them properly, but in 1867 Sultan Abdülaziz toured the museums of Paris, London and Vienna and saw what was needed. The main collection is in a grand neo-classical building of 1891, with two annexes for ancient art and Islamic art. Exhibits include Sumerian tablets, pieces of the wall of Babylon, Roman statues, and the sarcophagus of Alexander the Great, which he never lay in.

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.

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.

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.

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.

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.

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.

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.

Chora means countryside, and when built as a monastery in the 4th century it stood outside the Constantine walls; a century later, it was incorporated into the Theodosian walls. It was rebuilt in the 11th century then wrecked by an earthquake, so the structure and fabulous mosaics you see now are 14th century. When the church was converted to a mosque in 1500 the mosaics were plastered over, and only restored in 1958 when it became a museum. In 2020 it was again proclaimed a mosque but here (unlike Fethiye Mosque) they saw the sense and tourist income of preserving the mosaics. You need to work around prayer times.

A nice, organized museum with contemporary installations. It may be seen as overpriced given its small size. It also has a simple cafe.

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.