Pera Museum

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.

This was built in the 1430s by Grecian Jews ("Romaniotes") from the city of Ohrid, now in North Macedonia. The district of Balat was a Jewish quarter, swelled from 1492 by those expelled from Spain. The synagogue is only open for pre-arranged tours.

Named after a 16th-century village, founded by Serbs deported from Belgrade when it fell to the Ottomans. The village was popular as a forest resort, but its inhabitants were resettled in the 19th century and it's now a bosky ruin. The forest is mostly primordial and deciduous, predominantly oak. It's dotted with ancient aqueducts and dams as this area was a water catchment for Constantinople / Istanbul, and has lots of walking jogging and cycling trails and picnic areas. The two main ways in are via Bahçeköy (near the Arboretum entrance) and Kemerburgaz (which has the best aqueducts). There's a small access toll. The forest is supposedly a protected area but is being encroached on by highways and suburbs: this is likely to get worse as the access route to Istanbul's new airport leads right through it.

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.

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.

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.

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.

Built as the Church of Saints Sergius and Bacchus around 530 AD, the same time as Hagia Sophia, but their styles differ. Transformed into a mosque in the early 1500s, it's beautifully decorated, with fine marble details, and has a pleasanter atmosphere than the larger busy mosques. The adjoining madrasa houses craft shops.

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.

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

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.

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.

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.

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.

This lavish palace with 285 rooms and 43 halls was the admin centre for the Ottoman Empire in its last 60 years. The palace government block (Selamlık) includes the Imperial Mabeyn (State Apartments) and Muayede Hall (Ceremonial Hall), while the Imperial Harem was the sultan's private quarters. Also here are the Painting Gallery, Music Museum, Clock Museum and Museum of Palace Collections. Free audio guide in several languages available by the ticket office. No photography inside, no backpacks but you can leave them in the cloakroom. Allow 3 hours to see everything.

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.

The only active Ashkenazi Synagogue open to visits and prayers.