WHAT: Discovering the unique architecture of Chicago.

The boat glides under the Michigan Avenue bridge and heads into the heart of the city, as the shimmering white Wrigley Building and neo-Gothic Tribune Tower rise to the north. It passes the corncob-like Marina Towers, the sprawling Merchandise Mart and glass-and-steel skyscrapers — a tapestry of new and old that draws architecture enthusiasts from around the world to the city that famed architect Daniel Burnham once called his "Paris on the prairie."

The city's rise in the world of architecture began after the Great Chicago Fire of 1871 destroyed swaths of buildings, and the late 19th century saw the city's architects become world leaders — designing everything from the employee-packed skyscrapers to quaint homes that now make up the so-called Bungalow Belt.

Isolated from the East Coast's European influences, Chicago's historic architects were known for putting aside common ideas about design, creating a unique and different way of building. So innovative were their ideas that Chicago is considered the home of the modern skyscraper. Among the most famous are the 110-story Sears Tower — the tallest building in the U.S. — and the Hancock Tower, along Lake Michigan.

"We have always thought big," says Charles Stanford, a docent and architecture expert with the Architecture Foundation, which offers many tours. "Chicago was always bold about the way we built."

ARCHITECTURE FOUNDATION TOURS