Bath exists because hot water comes out of the ground here, about a million liters a day at around 46°C, and nowhere else in Britain does that happen. The Celts made the spring a shrine to their goddess Sulis, the Romans built a temple and a bath complex around it, and in the 1700s the spa came back into fashion and the whole city was rebuilt in honey-colored stone as a resort for the rich, with crescents, terraces and assembly rooms where Jane Austen's characters go to dance and gossip. It's one of the few places in the world where an entire city is a UNESCO World Heritage Site.
It's small, about 95,000 people, and you can walk across the center in twenty minutes. That's exactly why it works for five days: the Roman Baths and the Abbey take a day, the Georgian Upper Town another, and the rest is slower, a canal towpath, a riverside garden, a pub with a fire and a soak in the hot spring on a rooftop. It also sits in the middle of some of the best day trips in England, with Stonehenge an hour away.
This plan starts on a Wednesday. Day one is the Roman Baths, the Abbey and the rooftop pool, day two the Georgian Upper Town and the Royal Crescent, day three Pulteney Bridge, the Holburne Museum and the canal, day four Stonehenge and Salisbury, and day five, a Sunday, a landscape garden, a roast and a tower on the hill, which only opens at weekends. For the bigger picture, see our page on the United Kingdom.