Bands Hatch and Siverstone are in England. Europeedway Lausitz is in Germany and a little side trip to the Brno Curcuit in the Czech Rep. should get you going. Brno and Brands Hatch are pretty cool but I've not been to the other two.
Go to the old Nurburgring. You can buy a pass and just ride right on off the street.
Some things in Europe are just amazing. Other things suck beyond belief.
Nordschleife public access
The Nordschleife has remained a one-way public toll-road for nearly 80 years. At a slightly reduced length of 20.8 km (13 miles), bypassing the modern GP-Strecke, the Nordschleife is frequently closed off for testing purposes, training lessons or racing events. In the evenings and on Sundays, it is opened for the so-called "Touristenfahrten", i. e. to anyone with a road legal car or motorcycle, as well as tour buses, motorhomes or cars with trailers. This Nürburgring version is a popular attraction for many driving and riding enthusiasts from all over the world, partly because of its history and the considerable challenge it still provides. The lack of oncoming traffic and intersections sets it apart from regular roads, and the absence of a general speed limit, like on parts of the German Autobahn network, is an additional attraction mainly for foreigners. Accidents are common, though, and those considering driving around the Nordschleife should familiarize  themselves beforehand with rules that apply, as well as the "do's" and "dont's".
brands hatch for sure....donnington in the midlands ..the nurburgring definitely, they charge like a toll booth at the start of the lap just watch out for the oil patches where the cars blow up and spill their guts all over the road..and if you can get across to the isle of mann for the tt you can race the course on mad sunday..and most of the roads outside the villages have no speed limits all year round ...that should keep you occupied
IOM is something every rider should see once in their lives. Unfortunately, our intrepid traveler is ging in August.
In general, the riding on European roads is at a much faster pace than on American rural roads. I lived in Europe for 10 years, and really never felt the need for a trackday. Never got a ticket either.