Baku, sometimes spelled as Baki or Bakou, is the capital, the largest city, and the largest port of Azerbaijan and entire Caucasus. It is located on the southern shore of the Absheron Peninsula, that projects into the Caspian Sea. Baku's urban population at the beginning of 2009 was estimated at just over two million people.

The city also serves as the main economic hub of Azerbaijan. Many sizeable Azerbaijani institutions have their headquarters there. The Baku International Sea Trade Port is capable to handle two million tons of general and dry bulk cargoes per year.

Baku is home to the Shirvanshah's Palace and Maiden Tower which along with The Inner City of Baku were inscribed as a UNESCO World Heritage Site in 2000. According to the Lonely Planet's ranking Baku is also amongst the world's top ten destinations for urban nightlife.