I just got back from 3 weeks in the UK, in London and Cambridge.
I bicycled everywhere. I did not bother with a car.
In particular, I rented a Brompton folding bicycle. It folds in thirds, and fits in the overhead on most buses and trains and subways in the UK, and presumably Europe. It also fits in the overhead of larger airplanes, though not small regional jets.
https://us.brompton.com/
I stopped by the manufacturer in London - it's all old guys brazing up bicycles like they did 100 years ago.
Anyways, this made the UK very very fun and explorable. I spent several weeks in Cambridge, and was easily able to head to St. Ives and Ely from there. Riding in the city was faster than Uber/cabs, or driving myself, and vastly better than walking.
I liked the insane stupid clown bike so much that I brought one home with me. It has been doing fine here on my much much hill-ridden island, though I have ordered a new crank sprocket with a -12% gearing for our mountain. I managed to complete (in last place) our weekly community bike ride, which is not an easy course, on the clown bike.
I'm 56 with bad knees and ankles.
Anyways, the ability to have a bike small and light enough you can just carry it into a coffee shop, museum, or train is sort of revolutionary. I used it for a day in Seattle upon my return, and except for some of the insane Seattle hills, it was very freeing.
I have now taken several trips in my small 16-foot Boston Whaler with the Brompton tucked inside a small Ikea bag, to visit nearby islands and the mainland, and it is kind of life-changing for my particular circumstances.