Aon Center

The third tallest building in Chicago, on Open Day, you can see the panorama of Chicago. It's great. The Cloud Gate of Millennium Park is really smaller than beans in such a high place. People become little ants.

The headquarters of Aon Group was the tallest building in Chicago when it was completed. It was replaced by Sears Tower. The building was square, simple but magnificent.

怡安中心算是怡安集团的建筑，整个建筑就是摩天大楼，是当时的第一高，非常霸气，推荐看看。

这在芝加哥中心一定要好好的去参观一下怡安中心，挺棒的。

He was the tallest building in Chicago, and later Hills Tower surpassed his height, but it was still very tall. The building is rectangular, with a white stone surface and a two-inch thick Flagstone slab.