The US$300m (£193.5m, 220m euro) Modern Wing at the Art Institute of Chicago, US, has opened to public this week.

The 24,500sq m (264,000sq ft) extension, designed by Pritzker Prize-winning architect Renzo Piano has increased the museum's floor space to more than a million square feet, making it the second largest art museum in the US.

The three-storey extension, which is covered by a sun-shade system allowing natural light to flood into the building, showcases the institute's collection of modern European painting and sculpture as well as contemporary art, including film, video and new media.

Additional exhibition and gallery space provides three times more area to house the museum's Department of Architecture and Design and the Department of Photography.

An interior garden provides room for rest and contemplation, while an open-air sculpture terrace featuring rotating contemporary sculpture exhibitions overlooks Millennium Park, which is also linked to the museum by the new Nichols Bridgeway.

New visitor amenities include a new museum shop, a mezzanine café and the Terzo Piano restaurant managed by Spiaggia chef Tony Mantuano.

Access to the Bluhm Family Terrace featuring exhibitions on contemporary sculpture and to the Ryan Education Center - completely renovated to provide five classrooms, three studios, a family orientation room and a dedicated children's shop - is free to the general public.

"To say this is a historic moment in the history of the Art Institute is almost an understatement," said James Cuno, president of the museum.

"With an entire new building devoted to the museum's collection of twentieth- and twenty-first century art and design, we can now take our place as one of the leading encyclopedic collections in the country that has also remained steadfastly committed to collecting the art of our time.

"We are particularly excited to renew and expand our commitment to our visitors. With free and open access to the Ryan Education Center and the Bluhm Family Terrace, as well as our Chicago resident discount, we hope to serve the city and its citizens better than ever before."