Yesterday I learned its name. It's called Haysden Country Park. We went there yesterday on a whim after the appointment at the opticians. It looks rather different at ground level. There are woods, watermeadows, running water, standing water, a well-appointed play area and a café that serves very good food- including home=made ice lollies; the grandkids would love it.
The water is provided by the river Medway. In the 1830s there was an attempt to straighten the river's course between Tonbridge and Penshurst by putting in a canal. When this failed the engineer- a Mr Christie- remembered a pressing engagement in America, leaving behind the scars of excavation and a large empty lock built of huge stones that may or may not have been nicked out of Tonbridge Castle. Later the area was mined for sand and gravel.
The sand and gravel people moved out in 1980 and the Haysden Valley- or whatever it was called back then- was left as a post industrial mess. A major road went over it, a river and railway went through it. There was a weir on the river with a pool where people bathed and boated and fished; they called it Tonbridge Lido and it was in danger of collapse.
Someone decided this just wasn't good enough.
There was a plan, there was landscaping, paths were put in, trees planted, the gravel pits became lakes...
Barden Lake, Haysden Country Park, Tonbridge
(The information in this post mostly comes from a leaflet picked up on site.)