Galata Tower

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.

Situated on the gentle hill overlooking the neighbourhood of Emirgan and the Bosphorus, Emirgan Park was for long the only place in the city where Istanbulites can admire the beauty of tulips. Having lost that distinction since the first decade of the 2000s as tulips are now everywhere, this is still a beautiful park with artificial ponds, small waterfalls, and impressive views of the Bosphorus. There are also cafes with open-air sections housed in pleasant former imperial hunting manors. Squirrels are there, too, in the middle of this metropolis of more than 15 million people, though you may have to look a bit deeper (or a bit upper on the branches!) to spot them.

It was built in 2001 and is the first miniature park in Istanbul (the world's largest miniature park in respect to its model area). The park hosts icons of many cultures and civilizations. Models vary from the Hagia Sophia to Galata Tower, from Safranbolu Houses to the Sumela Monastery in Trabzon, from Qubbat As-Sakhrah to the ruins of Mount Nemrut. In addition, some works that have not survived into the present, such as the Temple of Artemis, the Halicarnassus Mausoleum and Ajyad Castle, were recreated. All former Ottoman Empire in one place.

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.

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.

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.

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

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).

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.

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.

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 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 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.

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.

About 15 minutes walking north of Beylerbeyi lies the historical fishing village Çengelköy. Its long history is attested by an 800-year-old sycamore tree on one of the two main terraced squares, and the Byzantine Aya Yorgi church. The restaurants and piers of Çengelköy offer some of the best panoramas along the Bosphorus, including a view on the old city under the first bridge. The neighborhood was popular amongst TV directors during the 1970s and it has become a (possibly the most) popular location to have lunch or dinner on the eastern side of Istanbul. Many historic mansions have been restored and multiple boutique chocolatiers were opened. Most restaurants in Çengelköy don't offer alcoholic beverages. Exceptions include the restaurant at the main pier (Iskele), and Tapasuma, the restaurant of hotel 'Sumahan on the Water', located in a former Ottoman Raki distillery. You can get there by taking bus 15 or 15F from Üsküdar, it is just a few stops further than Beylerbeyi. Going to Çengelköy by car is not advised; traffic can be very intense on the narrow road along this side of the Bosphorus.

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.

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.

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.

This is a triple structure: the church of the Monastery of Pantokrator built 1118, then a public church circa 1136 plus a chapel that served as a royal mausoleum. It became a mosque and medresse in Ottoman times, but without massive alteration so it's a prime example of middle-Byzantine architecture. It's nowadays again a mosque, photogenic by day or dusk but the area should be avoided at night.