Dogging, according to Wikipedia, is a British expression for engaging in a public display of sex.
It usually happens in a car, and it's got a whole set of rules that we don't even want to get into.
But annnnyway. Each to their own and all that.
What we stumbled upon on our (ahem, research) was that there is a website that showcases all of the best dogging spots in the country - county by county.
And here they are...
The website looks like this, and give you the opportunity to search your county, add your own location and even join up for free.
Now finally you have an explanation as to why certain car parks look fuller at night...