If you are not from the UK or Ireland, the first reliable tell is often traffic flow: cars approaching from a direction that feels reversed, roundabouts that behave like polite social contracts, and road markings that include shades of yellow you do not see in the continental palette the same way.
England, Scotland, Wales: shared habits, different stone
Terraced housing and hedgerow suburbs can appear across borders, which is annoying in the best way. Use secondary cues: bilingual signage in Wales, Scottish civic branding, London’s specific red bus grammar when you are lucky enough to catch it in frame.
Ireland: don’t flatten it into ‘UK but green’
Irish road furniture and signage carry their own standards. Gaelic appears in deliberate pairs with English. When the light goes soft and the stone walls go stubbornly local, Ireland stops being a guess you make from vibes alone.