Chicago Millennium Park, a large city park and post-modern architecture are another landmark attraction in Chicago. On one side of the park is Chicago's busy Michigan Avenue, and on the other side is Lake Michigan. The "Yindou" Yunmen, "Spray" Open-air Concert Hall and "Face" Crown Fountain are the three most representative post-modern buildings in Millennium Park. Cloud Gate is made of 168 stainless steel plates welded together, but the surface is very smooth, no seams can be seen. Smooth Cloud Gate reflects the sky, the city's high-rise buildings, forming a unique distorted picture, amazing.