I have a clock, but I never tick or tock. What am I?I have a tower that leans to one side, but it's not Pisa. Where am I?I am a river that flows through the heart of the city, what am I?I am a famous bridge that opens up to let large boats pass through. What am I?I am a palace where the royal family resides. What am I?I am a giant wheel that offers a bird's eye view of the city. What am I?I am a famous underground system that spans across the city. What am I?