If you are in the States, you cannot miss Chicago, home of the steel-framed skyscraper. There is an architectural tour through the Chicago river by boat. I highly recommend it for architects. The guide will explain you interesting stories building by building all across the canal. It starts in one of the sides of DuSable Bridge. If you find tickets during the sunset, go for them! It is a nice moment of the day and there is a special light. The tour continues to the Trump Tower, one of the Mies towers and the Marina City, with a spectacular corn shape.
The NeoCon is a huge building where they project every day in the façade at 9 pm some stimulating images from local artists. Also, you will discover the new tower developments with interesting and complicated structures in the first-floor due the railroads underneath them. You will see the Willis Tower (Sears Tower years ago) from a new point of view. Then the boat continues to the harbor (The USS Chicago Anchor). You will see the foundation of the failed Chicago Spire by Santiago Calatrava that was cancelled during the Recession of 2008. Also in this part of the trip you will see the two highest towers in the world designed by an architecture office lead by a woman, Jeanne Gang. One of the most spectacular things of this trip are all the movable-bascule bridges. The first one was built in 1902. Their construction made possible the incredible expansion of the city to become one of the biggest metro areas in the world. Apart from that, the Riverwalk Park is a new incorporation to the city, full of bars and nightlife just in the border of the canal, it is a great point to start a nice walk admiring all the Chicago architecture. I hope you enjoy this city, it really worth it!