The Stavros Niarchos Foundation Cultural Center (SNFCC), designed by Renzo Piano, has opened in the Greek capital city Athens with a four day festival of cultural events.

The building – one of CLAD’s most anticipated of 2016 – is a multi-functional and environmentally sustainable education, arts, and recreation complex which houses the National Library of Greece and the Greek National Opera in separate wings.

The building features a sloping grass roof which visitors can climb to access a glass-walled Reading Room and a 360 degree viewpoint over the city and coast. This links at the bottom to the 210,000sq m (2,260sq ft) Stavros Niarchos Park, created by landscape architects Deborah Nevins and Associates.

The complex is aiming for a LEED platinum rating. Natural ventilation is being extensively used and the building’s canopy roof is topped with 10,000sq m (107,000sq ft) of photovoltaic cells. The architects say this will generate 1.5 megawatts of power.

Alongside the centre, a wide canal has been built as a figurative extension of the adjacent sea, and an anti-flooding window for the whole site.

The SNFCC is a gift by the Stavros Niarchos Foundation (SNF) to the Greek state – one of the largest donations in Greece’s history – and will be operated by the government. The total cost of the project is approximately US$816m (€738.5m, £595m). The SNF was founded by the late shipping magnate Stavros Spyros Niarchos – considered one of the most innovative and successful businessmen of the 20th century.

Proud to be Greek. An excellent new Stavros Niarchos Foundation Cultural Center #snf #Greece #snfccmetamorphosis pic.twitter.com/imI9VXA2Xs

— Aris Kamvisis (@AKamvisis) June 23, 2016

The opening festival, called Metamorphosis: The SNFCC to the World, has transformed the centre into “an open space of encounter, exploration and experimentation.” Cultural, sports and educational activities are taking place, involving more than 400 Greek and international artists.