The Calton Hill Play Shelter is a modular and demountable structure designed by Scottish practice O'DonnellBrown for the Collective contemporary art centre in Edinburgh, Scotland.

Located at the World Heritage Site of Calton Hill, the 25-square-metre shelter stands in a flagstoned courtyard outside the art venue, which is housed in a 19th-century observatory.

The observatory, which was designed in 1818 by William Playfair to evoke a Greek temple, had previously stood empty until its transformation into an arts centre by Collective Architecture in 2018.

Glasgow-based O'DonnellBrown designed the play shelter to host a variety of activities in Collective's learning programme, including loose parts play and creative events for families.

Calton Hill Play Centre is the latest in a series of shelters by the studio that is designed to promote outdoor learning during the coronavirus pandemic. The others include the Rainbow Pavilion and the Community Classroom in Glasgow.

"The play shelter demonstrates the adaptability of the design principles employed in our Community Classroom project applied to a highly sensitive location," said O'DonnellBrown co-founder Sam Brown.

The core structural approach used in these previous outdoor learning projects has been applied at the Calton Hill Play Shelter, which is designed to stay in place for a minimum of three years.

"The client has been a joy to work with to knit it into the historic context, creating a harmonious built addition which also follows circular economy principles," Brown added.

O'DonnellBrown drew from the classical City Observatory opposite to determine the proportions of the whitewashed timber frame, which is constructed from bolted columns that can be easily dismantled.

"The rhythm and proportion of the surrounding 19th-century classical architecture determined the spacing of the columns and height of the roof," explained the studio.

A polycarbonate roof covers the shelter and is slightly elevated to create a clerestory-level gap.

Wooden panels infill some of the gaps between the columns, while others are left open to provide a number of routes into and out of the space.

To conceal Calton Hill Play Shelter's steel footings, the courtyard flagstones were temporarily removed and put back in their places to minimise the shelter's impact.

The existing stone wall around the perimeter of the observatory conceals the shelter from view to the outside, as well as protecting its open interior from strong winds on the site.

O'DonnellBrown is an architecture studio that was founded in Glasgow in 2013 by Jennifer O'Donnell and Brown.

Its outdoor classroom prototype, first established at the Community Classroom, is now being manufactured by furniture and design company Spaceoasis.

The photography is by Ross Campbell.