The capital of Azerbaijan is Baku, which is a four-letter word. Baku is the largest city in Azerbaijan and is located on the southern shore of the Caspian Sea. It is the cultural, scientific, and industrial center of the country and is home to many universities, museums, and theaters. Baku has a long history, having been inhabited since the 8th century BC. It has served as an important trading post for centuries and was once part of the Silk Road. Today, Baku is a modern city with a vibrant economy and a growing population.