Reference

Here are some notable buildings in Chicago that have more than 20 floors:

1. Willis Tower (formerly Sears Tower) - 110 stories, 1,451 feet tall. It's one of the tallest buildings in the world and a major landmark in Chicago. More info.

   

2. John Hancock Center - 100 stories, 1,128 feet tall. This building features a distinctive design and is known for its observation deck offering stunning views of the city. More info.

   

3. Aon Center - 83 stories, 1,136 feet tall. It is one of the tallest buildings in Chicago and has a distinctive white marble façade. More info.

   

4. Trump International Hotel and Tower - 98 stories, 1,389 feet tall. This mixed-use building includes a hotel and residential units. More info.

5. NEMA Chicago - 76 stories, 896 feet tall. A residential building known for its modern design and amenities. More info.

   

6. BMO Tower - 25 stories, 1,000 feet tall. A relatively new addition to the Chicago skyline, primarily serving as office space. More info.

   

These buildings are just a few examples of the many high-rise structures that define Chicago's impressive skyline. If you need more detailed information about any specific buildings or other buildings over 20 floors, let me know!