For those who aren’t xenophobic dinosaurs there was a particular magic to driving across multiple open borders in Europe and feeling part of it all. Impossible for Brexiters to understand I guess.
The old East German border crossing Checkpoint Alpha at Helmstedt–Marienborn, now abandoned but visitable with a small museum. There were four of these mobile crash barriers each able to stop a speeding lorry.
When you arrived at the crossing your passport was sent along these conveyor belts and checked by the Stasi. It was a very threatening place - not possible to capture the atmosphere now.