The Triangle Adventure Playground was established in 1957 by Marjorie Porter MBE in collaboration with Lady Allen of Hurtwood and the London Council. Of the first four APGs to be established in England, only two now exist in name and the Triangle is the only one still operating on its original site.


It is thus the oldest adventure playground in the country.

Lady Allen holds an important place in the development of play theory within the wider context of the history of education. Born in 1897 and trained as a landscape architect, she came across the concept of 'free play' whilst working in Europe to improve the lot of displaced children in the aftermath of the Second World War. Passing through Denmark, she visited a revolutionary playground, at Emdrup, outside Copenhagen, that had been established in 1943 by the architect C Th. Sorenssen. The ethos of this playground, reflected in what in its time were its dramatically informal physical characteristics, recognised, encouraged and celebrated the inate ability of children to direct their own activities. Sorenssen had recognised that 'Play', far from being 'just kids' play', just kids 'mucking about', is the manifest reflection of a profound and subtle process whereby both physical and social skills are developed amongst peers and without adult intervention. Now a thoroughly researched and understood idea - that children need not be subject to what was thought good for them by grownups - in Lady Allen's time this was a disturbing and revolutionary notion, embraced in the main only by a handful of radical 'free-thinkers'. Amongst these was the young Marjorie Porter, then embarking on her first employment as a Head Teacher at a brand new primary school in Lambeth.

The site for the Ashmole Primary School and the adjacent Triangle was cleared of slum dwellings as part of the regeneration of London undertaken by the LCC following the Second World War. Unlike many APGs that were to follow, the Triangle was never a bomb site. It was established by the energetic Mrs Porter on land cleared for, but surplus to, the requirements of her new primary school.
As was typical of the early APGs, the Triangle has never been operated by its borough council but is managed and funded by a fiercely independent committee drawn from its local community. Its longevity and success is the result of its continuing adherence to the ethos and values of its founders. The Triangle was in the vanguard of a movement that profoundly influenced the way in which society now understands and educates its young.

There is a very strong need for that adventure playground (Triangle) to be there.
— Kate Hoey MP 2010