Ahrida Synagogue of Istanbul

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 small town 40 km west of central Istanbul and 15 km north of Büyükçekmece that had a substantial Greek population until the 1920s transfers. Spared from destruction in the Balkan wars which foreshadowed the Great War, the old quarter has many historic wooden buildings and fountains in leafy squares. A short stretch of the old town walls still stand just north of the centre. In the outer areas, bunkers of the WW2 'Çakmak Line' and remnants of the Byzantine Anastasios Walls could be observed. The town's main sight, housed in a red brick neoclassical building erected as a Greek tavern, this museum commemorates the forced population transfer of 1922–26, whereby Greeks living in Turkey were expelled to Greece, while the Turks of Greece were expelled to Turkey.

A charming domed church built in 1880 at the side of Taksim Square, now uneasily contesting with Taksim Mosque for being the main landmark of the southern edge of the square.

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.

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.

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".

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).

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).

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.

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.

Among the exhibition of this museum are five thousand pieces from the Ottoman era through WWII, with the most prominent piece possibly being the huge chain that the Byzantines stretched across the mouth of the Golden Horn to keep out the Sultan's navy in 1453 during the siege of Constantinople. In the yard of the museum, the Janissary Band (Mehter Takımı), the world’s oldest military band gives concerts of march music in traditional uniforms each afternoon, at 15:00.

This is the main attraction around this part of the city. The holiest Islamic shrine in the city, the complex includes, right next to the mosque, the tomb of Abu Ayyub al-Ansari (Eyüp Ensari Türbesi), the standard bearer of Prophet Mohammad, died and buried here during the first Muslim siege of Constantinople (674-678 AD). The neighbourhood was named after him. Muslims flock here (in such huge numbers that sometimes you have to queue for a few minutes before entering the tomb) also to see a rather uninteresting plaque made of plastic, which is purported to be Mohammad's footprint. The interior of the tomb, covered with fine tiles/faience, is nonetheless well worth a look, however. It is also interesting to see the devout Muslims leaving the place by walking backwards through its exit hallway, as not to turn their backs to al-Ansari's catafalque, though obviously no one expects everyone to quit the place in the same manner.

The "Polish village" was founded in 1842 by Polish settlers in the wake of the failed uprising against Russian Imperial rule, and reinforced by more settlers after every subsequent civil upheaval until Poland's independence in 1918. Most then returned, but several stayed on, adopting Turkish citizenship but maintaining their Polish language and culture. The village has houses in traditional Polish style, a 1914 little Catholic chapel, and the Church of Matka Boska Częstochowska. It's set in woodland (a nature park) and is a popular day-trip from the city. There's four restaurants and half a dozen small hotels, plus more of each in nearby Beykoz.

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

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.

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.

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.

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.