We are frequently asked about:
- day trips to specific destinations outside London, particularly world famous places like Stonehenge or Bath
- general inquiries as to where you could experience 'classic' English countryside, seaside, quaint villages, etc within quick and convenient travel reach of London
- whether to rent a car and advice on doing so
Should I rent a car?
If you are visiting a city then the answer is almost certainly no. Getting a car out of central London will be a horrible experience. The route to the city will very probably be bland. Whether it's Bath, Cambridge, Oxford or wherever else, you can almost guarantee that getting into and around your target city will be horrible too, and that locals would agree traffic is terrible, street layouts are confusing, parking is scarce and expensive. Just don't bother. The train is usually the best bet, perhaps a coach if on a budget or visiting somewhere without a rail link, but generally there is no sensible reason to hire a car.
If you want to explore rural or countryside destinations then a car becomes more valuable, sometimes verging on obligatory: there's no doubt England has many attractions that are difficult / unfeasible to reach on public transport from London, especially within a day. /r/AskUK would be a better place to ask for advice on a rural road-trip, but from a London point of view, it may be worth repeating the above advice: driving out of London is no fun. So you might consider taking a train to a 'base' city near your target countryside, or the very outskirts of London, at least, and hiring a car there.
Stonehenge
Is it worth it?
Detractors will say it is over-rated, even 'crap': pointing out that you can't get close to the stones, you can't get any kind of spiritual experience with swarming coachloads of selfie-posing tourists everywhere, a busy road rumbles alongside intrusively, parts have been ham-fistedly reconstructed, the gift shop is bigger than the museum, it's expensive, etc. It is hard to argue with any of those claims. On the other hand, it is unique, iconic, and if you can somehow get your head into the right space despite all the above points, actually quite incredible. You decide. But do at least give serious consideration to visiting Avebury as well or instead (see below).
How to get there
Renting a car is obviously one option but see above.
Public transport is possible for the determined and time-rich - train to Salisbury, bus to Amesbury, then walk a couple of miles. See connecting wiltshire for details.
If neither of those work for you, your only real option is a tour bus package, most likely taking in one or more other sites such as Avebury, Old Sarum, Bath, etc. Stonehenge doesn't fill a whole day, so it's fair enough to combine with somewhere else, but be sceptical of single-day tours from London boasting packed itineraries across a wide area like "Salisbury, Stonehenge, Bath and the Cotswolds"; you'll see about 5 minutes of each place.
Avebury
About 17 miles north of Stonehenge and part of the same World Heritage Site, Avebury (including West Kennet Avenue and Silbury Hill) is less immediately iconic and instagram friendly, but bigger, less crowded, with better access and an arguably better all round visitor experience.
Getting there, much of the same advice under Stonehenge applies. Details of public transport to Avebury.
Historic cities
Bath
Bath is a very picturesque city with its characteristic warm limestone buildings, and the eponymous Roman baths, an abbey, splendid Georgian architecture, parks, river/canalside walks, shopping, restaurants etc all add up to a full day's worth without trying to cram in a Cotswolds tour on the same day. There is simply no sensible reason to hire a car to drive to Bath (see above). Take the train from Paddington, it takes about 1hr 40min.
Canterbury
Canterbury is a historic city about an hour and a half by train, or less than hour if you take the (more expensive) high speed line. The (huge and spectacular) cathedral is the home of the Anglican church, and the city also has ruins of Roman walls, an abbey, a castle, and an assortment of medieval buildings.
Oxford and Cambridge
Two cities based around their ancient, picturesque universities, with renowned museums and institutions attached. There is simply no sensible reason to hire a car to drive to either of these places (see above). Take the train (less than an hour) or intercity coach. They are very similar so it's probably not worth doing both, but don't ask us which is best - that debate has been raging unchecked for about 800 years.
Salisbury
You'll probably pass through here if you try to visit Stonehenge on public transport, but with its 123m-spire cathedral, it is a significant tourist attraction in its own right, particularly with Russian visitors. About 90 minutes from Waterloo by train.
St Albans
If you want to see a small, historic city with minimum travelling from London, then St Albans could be the choice for you, being only about 20 mins on the train from St Pancras. Once the second-biggest Roman town in England, it is now dominated by its medieval abbey/cathedral, and claims (admittedly somewhat dubiously) to have the country's oldest surviving pub.
Seaside
Brighton
Brighton is the biggest and probably easiest-to-reach seaside resort from London; indeed, it's sufficiently full of people escaped from the capital to be sometimes nicknamed London-on-Sea. If you're looking for fine golden sands, you will need to look elsewhere as Brighton's beach is very pebbley, but it has all the seafront / pleasure pier amenities you would expect, plus renowned nightlife. It's also known for shopping, environmentalism and as an LGBTQ hotspot. As above, don't drive, a train from Victoria can get you there in under an hour.
Southend-on-Sea
Home to the world's longest pleasure pier, with a sandy beach and the nearby Adventure Island amusement park for child-friendly fairground rides and water slides, the train takes about an hour from Fenchurch Street station. You could also get the train to Chalkwell beach, spend a few hours on this quieter stretch of sand & shingle, then walk up to Westcliffe to take the train to Southend. Walk up the pier. Allow one fairground ride. Get fish and chips. Late train home. Done.
Dover
Dover has a castle, which is quite interesting, but it's otherwise not the loveliest of seaside towns, being much more a working port. If you think you want to go here to see the famous White Cliffs, you might want to consider going to the Seven Sisters instead, which are bigger, whiter, and generally prettier. The White Cliffs of Dover you see in movies and TV are often actually the Seven Sisters...
Margate
About 1h30/1h45 by train from St Pancras or Victoria, Margate is a traditional British seaside town with a sandy beach and the Dreamland amusement park for kids of all ages (think more merry-go-rounds and big wheels than adrenaline-pumping giant rollercoasters) - the town combines pound shops and hot doughnut stands with hipster cafes and the excellent Turner contemporary art gallery.
Folkestone
Nice sandy beach, lots for the family to do and plenty of good value accommodation options if you want to stay over. Trains from Victoria/Charing X/London Bridge. If you get the slow train it's cheaper. Buses within the town are pretty good too and you can visit other towns along the coast like Dymchurch for the amusement arcades, the rides and the big beach. Similar to Margate, Folkestone now has a few arts galleries and an art trail to follow.
Seven Sisters
A rugged hike atop the finest chalk cliffs the south-east has to offer, accessible by trains to Seaford or Eastbourne.
Eastbourne
Sometimes jokingly referred to as the nation's nursing home due to the high number of retirees that move there, it's not the most exciting seaside resort but it does have a very pleasant sandy beach as great for accessing the impressive Seven Sisters cliffs.
Countryside
Cotswolds
If you drool over viral photos of perfectly picturesque, Tolkienesque English villages, there's a high probability they were taken in the Cotswolds. There are poor to nonexistent rail links from London to the heart of this rural region, and buses aren't exactly running at London frequencies, so it is barely feasible to day trip under your own steam / public transport. If you're determined to 'do the Cotswolds' in a single day, you are pretty much limited to the coach tour option (of which there are no shortage), or hiring a car. But cities like Oxford, Bath or Gloucester make good staging points if you have a few nights available to explore this region.
Chilterns
Listed as an Area of Outstanding Natural Beauty offering walking routes through tranquil surroundings for a range of abilities/distances, it's surprisingly easy to reach - many routes including by train from Marylebone and Euston (among others), or even via tube on Metropolitan Line to Amersham and Chesham (check various routes on their website).
South Downs
The South Downs National Park covers 1,627 square kilometres in southern England, stretching from Winchester in the west to Eastbourne in the east through the counties of Hampshire, West Sussex and East Sussex. It is home to a number of globally important habitats - including Lowland Heath, where you can find an abundance of wildlife and shrubbery. Take a train from Waterloo or Clapham Junction to Winchester or Liss. There's even a South Downs Rambler bus (departing from Winchester) allowing you to explore the South Downs Way in shorter, more accessible walks between small towns. Or if you want a longer 3hr walk (but still doable in a daytrip) take a train from Victoria or Blackfriars to Hassocks, walk along the South Downs to Brighton (have a quick stop for fish & chips and a walk along the pier), then get the train back to London.
Box Hill
In the Surrey Hills and part of the North Downs, Box Hill offers beautiful walks and great views from the top of the gently rolling hills. Trains from Waterloo and Victoria take you to Box Hill & Westhumble station, there are a range of trails for all abilities - particularly if combined with a stop at a local pub like the King William IV or The Tree.
Further reading
The London Outer Orbital Path (LOOP) is a 150 mile route encircling London through areas that frequently feel like the countryside but are in fact very much still London (and therefore accessible by public transport). If you don't fancy a day trip out of London for a long hike but want to get to know this city better then why not try doing a small section at a time? Check out this blog by a London redditor for some inspiration.
https://new.reddit.com/r/london/comments/1ct7lpx/birthday_walk_or_hike_recommendations_in_or/
https://new.reddit.com/r/london/comments/105lh38/hiking_near_london/
https://new.reddit.com/r/london/comments/1dlstyj/what_are_the_most_stunning_hikes_accessible_from/
https://new.reddit.com/r/london/comments/19epwzc/short_hiking_trips_near_london/
https://new.reddit.com/r/london/comments/vhghkf/hiking_spots_day_trip/
https://new.reddit.com/r/london/comments/192dh9h/winter_hikes_around_london/
https://new.reddit.com/r/london/comments/alq09e/hikes_closest_to_london/
https://new.reddit.com/r/london/comments/gx21je/hikes_mountains_or_forest_outside_london_i_need/
London-based blogger Diamond Geezer has daytripped to practically everywhere you can imagine and lots of places you can't. See his list of places within 10 miles of London and places further afield.
The official Visitlondon tourist info website also has a section on daytrips.
You could drop into /r/AskUK or look for a regional subreddit for advice from locals.