The document summarizes key details about the Hangzhou Bay Bridge in China. It is the longest sea-crossing bridge in the world at 36 kilometers long. It took 9 years and cost $1.7 billion to plan, design, and construct. The unique bridge has a service center in the middle with a hotel, restaurant, and observation tower allowing visitors to view the bay's large tides and waves. The S-shaped design allows it to withstand typhoons and hurricanes.