Istanbul is the largest city in Turkey, straddling the Bosporus Strait, the boundary between Europe and Asia. It is considered the country's economic, cultural and historic capital. The city has a population of over 18 million residents, comprising 19% of the population of Turkey, and is the most populous city in Europe and the world's fifteenth-largest city.
The city was founded as Byzantium in the 7th century BCE by Greek settlers Megara. In 330 CE, the Roman emperor Constantine the Great made it his imperial capital, renaming it first as New Rome (Latin: Nova Roma) and then finally as Constantinople (Constantinopolis) after himself.In 1930, the city's name was officially changed to Istanbul.
The city served as an imperial capital for almost 1600 years: during the Byzantine (330–1204), Latin (1204–1261), late Byzantine (1261–1453), and Ottoman (1453–1922) empires.The city grew in size and influence, eventually becoming a beacon of the Silk Road and one of the most important cities in history. The city played a key role in the advancement of Christianity during Roman/Byzantine times, hosting four of the first seven ecumenical councils before its transformation to an Islamic stronghold following the Fall of Constantinople in 1453 CE—especially after becoming the seat of the Ottoman Caliphate in 1517. In 1923, after the Turkish War of Independence, Ankara replaced the city as the capital of the newly formed Republic of Turkey.
Istanbul was the 2010 European Capital of Culture. The city has surpassed London and Dubai to become the most visited city in the world, with more than 20 million foreign visitors in 2023. The historic centre of Istanbul is a UNESCO World Heritage Site, and the city hosts the headquarters of numerous Turkish companies, accounting for more than thirty percent of the country's economy.

Blue Mosque in Istanbul, also known by its official name, Sultan Ahmed Mosque (Turkish: Sultan Ahmet Camii), is an Ottoman-era historical imperial mosque located in Istanbul, Turkey. It was constructed between 1609 and 1617 during the rule of Ahmed I and remains a functioning mosque today. It also attracts a large number of tourists and is one of the most iconic and popular monuments of Ottoman architecture.
The mosque has a classical Ottoman layout with a central dome surrounded by four semi-domes over the prayer hall. It is fronted by a large courtyard and flanked by six minarets.

Hagia Sophia is a work that was constructed three times in the same location. Today’s Hagia Sophia is known as the “Third Hagia Sophia”. The first construction of Hagia Sophia started during the reign of Constantine I, who accepted Christianity as the official religion of the Roman Empire. This building, which was constructed as a basilica with a wooden roof on the first of the seven hills of Istanbul and was called "The Great Church" at the time, was opened during the reign of Constantine II in 360. There is no remnant this structure, which was largely devastated as a result of a fire that broke out in the revolt that started in 404.

Byzantine Emperor Justinian I in the 6th century (532) constructed the Basilica Cistern to supply water to the Great Palace, the imperial residence, and other locations in the region. Before the current cistern was constructed, there was another cistern built there by Constantine I.
However, this cistern was severely damaged while a fire broke out in the region. Justinian I reconstructed and enlarged the ruined cistern and constructed the current cistern. The water for the cistern was transported through the Bozdoan Arch and other aqueducts the Belgrade Forest. There is also a water purification system inside each dome on the ceiling, designed with the special technology of the era.

In 1453, Sultan Mehmed II conquered Constantinople, renaming it Istanbul. Six years later, he initiated the construction of the 'New Palace,' now called Topkapi Palace, which was completed in 1465. Following earthquake damage in 1509, significant renovations and expansions were made. Suleyman I oversaw the completion of the second gate in 1529, enhancing the palace's grandeur. In 1665, a devastating fire prompted extensive renovations. By 1853, the palace ceased functioning as a royal residence and instead was turned into accommodations for high-ranking officers. Finally, in 1924, Topkapi Palace underwent a transformative shift when it was converted into a museum encapsulating centuries of Ottoman history and cultural heritage.

Dolmabahçe Palace is a grandiose and opulent palace located in Istanbul, Turkey. Commissioned by Sultan Abdulmecid I, it was built during the Ottoman reign and served as the main administrative center of the Empire. It houses over 285 intricately adorned rooms with crystal chandeliers and ornate ceilings. The palace also boasts a beautiful garden that offers stunning views of the Bosphorus River. Read on to learn more about the history of Dolmabahce Palace when it was built in 1856 to today.

The Galata Tower was originally built in 1348 by the Genoese as part of the fortifications protecting their colony. Originally called the Tower of Christ (Christea Turris), it served as a defensive fortress to help protect the Genoese settlement. The tower was a symbol of the Genoese presence and highlighted their maritime power in the Middle Ages.
After the Ottoman conquest of Constantinople, the tower was repurposed and continued to serve as a fire watchtower, a prison, a naval observatory, and most recently an observation deck.

In the fifth century BCE, a customs point was established on the island where the tower is located today, and a tower was built to inspect ships coming the Black Sea and tocollect taxes.
A defence tower was built on the island by the Eastern Roman Emperor, Manuel Komnenos the First, in the 12th century. A chain was stretched between this tower and a tower located next to the Mangana Monastery in Sarayburnu (the section where the sea walls were restored) to control the entry and exit of ships through the Bosphorus.

Istanbul's Grand Bazaar (Kapalı Çarşı) is Turkey's largest covered market offering excellent shopping. Covering a total area of 45000 sq. meters with approximately 4,000 shops, the Grand Bazar is definitely worth a visit if your path crosses Istanbul.
Anything beautiful Turkish carpets, to glazed tiles and pottery, copper and brassware, apparel made of leather, cotton and wool, meerschaum pipes, bookends and ashtrays, jewelry, and all sorts of other things can be found.