Walking into the Old City feels like stepping back in time. The lanes are too narrow for cars - just people, cats and the occasional bicycle. Houses are made of warm yellow stone, with wooden balconies that hang out over the streets. Some buildings have been homes to the same families for many generations.
The most famous building is the Maiden Tower, a round stone tower 8 storeys tall that has stood by the sea for over 700 years. Nobody knows for certain why it was built - it might have been a watchtower, an observatory for studying the stars, or something else. Climbing to the top today gives you one of the best views in Baku.
Right next to the tower is the Palace of the Shirvanshahs - a beautiful old palace with stone-carved doorways, secret rooms and a courtyard fountain. The kings (called shahs) who once lived there ruled this part of Azerbaijan hundreds of years ago. Today it is a museum, and children visit on school trips.
What makes Icherisheher really special is that the modern city wraps right around it. Step out of one of the gates, and suddenly you are on a busy street with cars, trams and skyscrapers. Step back through the gate, and the world goes quiet again. It is like having two cities sitting one inside the other.