The Skydeck attraction at the Willis Tower in Chicago – which held the title of the world's tallest building for 25 years – has reopened following an extensive redevelopment.

Designed by Skidmore, Owings & Merrill (SOM), Thinc Design, and Chicago Scenic Studios, the Skydeck forms the centrepiece of a visitor experience which also includes a new interactive exhibition showcasing how architecture has shaped Chicago’s history and identity.

On entering the 110-storey Willis Tower, guests are guided through the interactive exhibition, while a fly-through video by Squint/Opera provides an immersive tour of the skyline.

An elevator ride to the 103rd floor then reveals the transformed observation deck.

Interior enhancements, improved lighting and building technology upgrades allow for greatly expanded views across the city, while new interactive screens encourage visitors to learn more about Chicago’s historic architecture.

Along with the views, guests can indulge in informational videos about the city's growth, travel patterns, cultural attractions and the making and history of The Ledge.

Guests are invited to leave a mark on the city by creating drawings or messages on the interactive sequin wall.

The Skydeck was developed and led by EQ Office, the operator of Willis Tower, and constructed by RL Edward Partners and Clark Construction Group.

David Moore, senior VP, portfolio director at EQ Office, said: “Skydeck has always been the best way for locals and visitors to see all of Chicago, and now we have dramatically expanded and elevated the experience beyond what anyone has seen before.

"The new Skydeck experience celebrates hometown traditions and Chicago’s storied history, with incredible views that you can’t find anywhere else."

Randy Stancik, general manager at Skydeck Chicago, said: "With the reimagined attraction, we wanted to take that experience a step further.

"The new Skydeck tells the story of Chicago – from the Great Chicago Fire to iconic city legends – and allows visitors to actively engage with our beloved home in a way that is wholly their own.

"From interactive and educational installations to fun, photo-worthy moments, guests of all ages, backgrounds and geographic locations will leave with a newfound connection to Chicago and the incredible memories of our unparalleled views."