San Francisco's Exploratorium science museum officially unveiled its US$300m (228m euro, £197m) expansion at Pier 15 on the city's waterfront on 17 April.

The museum now has 330,000sq ft (30,658sq m) of floor space - trebling the footprint it had at its former home at the Palace of Fine Arts. It will display more than 600 exhibits.

Established in 1969, the museum is dedicated to science, art and human perception, and also offers film screenings, workshops and evening learning events, as well as professional development for educators.

Exploratorium is aiming for its new facility to be the largest net-zero energy museum in the US, if not the world, with the undertaking to be part of a real-time exhibit, showing live energy use and photovoltaic production data.

Other features at the site will include all-glass building The Bay Observatory and The Fisher Bay Observatory Gallery and Terrace overlooking the city.

Image: ZUM