This is also reflected in the city's nickname as the "City of Winds".
A less probable folk etymology explains the name as deriving from Baghkuy, meaning "God's town".
Between the 12th and 14th centuries, massive fortifications were undertaken in Baku and the surrounding towns.
The Maiden Tower, the Ramana Tower, the Nardaran Fortress, the Shagan Castle, the Mardakan Castle, the Round Castle and also the famous Sabayil Castle on the island of the Bay of Baku was built during this period.
The city walls of Baku were also rebuilt and strengthened.
By the early 16th century Baku's wealth and strategic position attracted the focus of its larger neighbors; in the previous two centuries, it was under the rule of the in Iran-centred Kara Koyunlu and Ak Koyunlu.
In the 1st century CE, the Romans organized two Caucasian campaigns and reached Baku.
Baku was the realm of the Shirvanshahs during the 8th century CE.
The city is bidding for Expo 2025 against Yekaterinburg, Russia and Osaka, Japan.
The city is renowned for its harsh winds, which is reflected in its nickname, the "City of Winds".
Clockwise: Details of the façade of the Ismailiyya building, Philharmony Fountain in front of the Magomayev Philharmonic Hall, a vessel on the Bay of Baku with the skyline of the city, and the Maiden Tower – clickable image) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region, with a population of 2,374,000.
Baku is located 28 metres (92 ft) below sea level, which makes it the lowest lying national capital in the world and also the largest city in the world located below sea level.