Baku is the capital and main commercial center of Azerbaijan. It's a city that's low-lying and built along the shores of the Sea of Azhdad. It's well-known for its old medieval walled city, which houses the Shirvanish Palace, a huge royal palace, and the famous Maiden Tower. It's also home to some of the most modern landmarks, like the Heydar Aliyev Center, designed by Zaha Hadid, and the three-pointed Flame Towers, which are made up of LED screens.