So, you’ve breezed through all of the top-notch attractions in London and you’re looking for a few more exhilarating experiences before your days in the city come to an end and you have to fly-away home.
Or, perhaps you’ve been here before on earlier visits and, having seen the iconic sites, this time you would like to explore a bit more off the beaten track.
Then, how about these 4 suggestions?

Greenwich
Float on a boat down the Thames to Greenwich or trek there on a train. Either way Greenwich is easy to reach from the city center and will provide a splendid half-day excursion. Deciding to spend the entire day there would be an excellent choice also.
Greenwich is ‘home’ to both the Prime Meridian and Greenwich Mean Time (GMT). The Prime Meridian is 0 degrees longitude. It is the precise point from which the two hemispheres, Eastern and Western, spread outward, and the “line” runs through Greenwich quite literally. You can see it at the Royal Conservatory. You can stand on it. You can have your photo snapped with one foot firmly in the Western Hemisphere and the other in the Eastern Hemisphere. After rushing to post to Facebook your unique ‘standing’ you can then learn about Greenwich Mean Time (GMT) and how the clocks of the world are set from the ‘ring’ of those here. Time ‘starts’ here!
You can see and explore the Cutty Sark, the celebrated historic sailing ship and fastest of its time.
Visit the Old Royal Naval College, and the extraordinary Painted Hall. A Baroque masterpiece known as Britain's 'Sistine Chapel', the Painted Hall boasts one of the most spectacular Baroque interiors in Europe.
How to Get There:
https://www.visitgreenwich.org.uk/how-to-get-here/
----------------------------------------------------------------------------
London Walks
So many stories in this fascinating city all waiting to be heard. You can choose from an extensive listing of topical walks and locations from the repertoire of the entertaining walking guides at London Walks.
These are not the ‘oh look there’ or ‘and on your right’ type of tours. These are walking tours through neighborhoods and via pedestrian thoroughfares unseen unless you are with a local who knows the paths.
All of these walking guides are quite the expert in the topic of their walks. Some are academics, others are professional actors. Some are poets, some are historians. What they all have in common is an expansive knowledge of the walk’s topic and an eagerness to converse and share with you and your fellow walkers.
The walks are usually about 2-hours long and always begin and end at a Tube Station, making it quite easy to navigate to the guide waiting for you and then back to your hotel at walk’s end. Often times the walks end in the vicinity of a pub and it is not unusual at all for walkers and the guide to stop-off afterwards for a pint.
It’s a great activity for someone traveling solo, or for small groups of traveling friends. My most enjoyable times and experiences in London have centered around London Walks.
------------------------------------------------------
Perhaps you fancy a Day Trip from the city.
How about up to Cambridge to visit one of the great universities of our world – University of Cambridge?

How to get there:
There are train services from several central London train stations.
Recommended: The Great Northern Thames Link Railway runs fast trains directly to Cambridge Station from London King’s Cross Station every few minutes throughout the day. It’ll take just under an hour, and costs 34 USD.
You can actually visit inside the various Colleges of Cambridge and their gardens mostly for free, though some may independently charge a small fee.
Stop-in at a local supermarket or food shop for some picnic-to-go items and then enjoy a relaxed lunch alongside the River Cam. You’re apt to be entertained by some leisurely punting along the river flow, a common sight.
Enjoy strolling the expansive and lovely campus. Once on a walk there, exploring down a lane, I happened past a doorway with an aged plaque noting that to have been the office of Stephen Hawking. Serendipitous surprises await!
----------------------------------------

Or perhaps you would like to pivot to another direction and head to the west for Salisbury and Stonehenge.
I must say, if you don’t mind, it would be my firm suggestion that you separate Stonehenge from an out-and-back excursion to Salisbury. This for two reasons. One is that Salisbury and its awe-inspiring and historically notable Cathedral can easily fill your day. Second, is that Stonehenge properly ‘done’ should be allowed more than half-a-day in your mind and soul. But if you must, then you can easily find Stonehenge guides and transport upon alighting from your Brit Rail coach at the Salisbury station.
Salisbury and Stonehenge
How to get there:
Trains to Salisbury from London 1 hour 40 minutes. Then tour bus to Stonehenge.
At the Cathedral see:
See one of the four original Magna Carta !
(Why are there so many Magna Cartas? https://www.bbc.com/news/uk-england-london-29101774)
See the world’s oldest working clock. It was made in 1386 and still ticks and rings today!
See Britain’s tallest spire.
Enjoy London – both in the city and out-and-about!