Officials on Saturday marked the 150th anniversary of Chicago’s iconic Water Tower, which has stood more than 150 feet tall in the heart of the Gold Coast neighborhood for generations.

The limestone tower, built in 1869 by architect William Boyington, is one of the few buildings to survive the Great Chicago Fire in 1871, making it “as much an icon of our identity as our lake or our flag, representing both our ingenuity, architectural heritage and boundless resiliency as a people,” Mayor Lori Lightfoot said in a statement.

“Just as our city has been shaped around it, it has also shaped us, bridging our past to our present, and continuously guiding our future for generations to come,” Lightfoot said.

To mark the sesquicentennial, the American Institute of Architects Chicago and other organizations served free cake outside the tower in Jane Byrne Park, with onlookers cheering as Lookingglass Theatre Company performers put on pop-up shows featuring music, acting, tap-dancing, unicyclists and other theatrics.

Across the street at the Chicago Avenue Pumping Station building — which also was designed by Boyington in a Gothic Revival style and built with yellow limestone quarried from southwest suburban Joliet — AIA Chicago and the city’s Department of Water Management gave lectures and tours detailing the city’s water management system.

Richard Lanyon, former executive director of the Metropolitan Water Reclamation District of Greater Chicago, described Chicago’s historical efforts to create a safe and sustainable water source.

Chicago’s water supply was polluted and inadequate to serve the city’s rapidly growing population in the 1860s, so chief engineer Ellis Chesbrough was brought on to find a solution, Lanyon said. Chesbrough, who had already designed Boston’s water supply structure, came up with 2-mile tunnels that extended into Lake Michigan and pulled clean water into the pumping station. From there, clean water would be distributed to city residents.

To offset pressure surges in the water, a 138-foot standpipe was constructed, and the Water Tower was built around it, Lanyon explained.

“There is no part of Chicago history that is as fascinating as the water story,” said lecturer John Maxson, former president and CEO of the Greater North Michigan Avenue Association.

”It’s truly an architectural survivor that’s been an inspiration to many,” Maxson said. “We all know that it was the only municipal building in town to survive the Great Chicago Fire, but it also survived developers trying to tear it down... and the city trying to tear it down to try and straighten Michigan Avenue.”

Other festivities included art exhibitions like the “Growing Community” gallery located inside the historic Water Tower, 806 N. Michigan Ave., which highlights community-run green spaces throughout the city. It will run through Jan. 5, 2020 as part of the 2019 Chicago Architecture Biennial.

Joan Pantsios, of Hyde Park, stopped by an open house at the Chicago Fire Station 98 at 202 E. Chicago Ave.

“I’m into architecture, so it’s very interesting to see how our water system was built and the technology behind it,” Pantsios said. “This is a fascinating behind-the-scenes look into how everything works.”