Public parks in the UK are surprisingly young; the first was the Derby arboretum, opened in 1840, followed by e.g. Victoria Park in London (1845). There are now around 27,000 in Britain. Perivale park itself was only created in the 1930s.
Here I want to note a much older genre, the Physik gardens containing medicinal plants that were used to promote the teaching of botany and served as sources of materials for apothecaries. The Vatican first created one 1447 and we recently visited a pharmacy in Tallinn (Estonia) which had gardens in 1452. There are two famous old Physik gardens in the UK, the one at Chelsea (opened in 1673) and the older example at Oxford which dates from 1621. Kew gardens, perhaps the most famous of all, is a mere youngster with its opening in 1759. All three are still magnificent places to visit.
Below is a gallery of some photos of our visit to OBG (as it is known affectionately) in mid August.