A Thames river cruise is a relaxing way to see many of the iconic sites of the city from what is still very much a working river.
There are two ways to do a trip.
Sightseeing boats, some of which have a descriptive commentary, leave from Westminster Pier on a regular basis. You can join these tours at other points on the river and some even operate a hop on / hop off service.
Alternatively, you can take a scheduled River Bus. This service caters for those who prefer to use the river to travel around the city. Most services have refreshments and wifi and you are guaranteed a seat. But no commentary.
To avoid a round trip and to add in some interesting sights, take a boat down to Greenwich. Here you can visit Greenwich Maritime, a World Heritage Site centred around the Old Royal Naval College on the river front.
Cross the road for the National Maritime Museum. Exhibits large and small cover global and British naval history.
Further up the hill you will find Greenwich Observatory, the original home of all things astronomical. The Prime Meridian is marked here with degrees of longitude starting from this point. Here you can stand with one foot in the eastern hemisphere and the other in the western hemisphere. Exhibits in the museum are astronomical and time based. Displays show the history of astronomy and timekeeping through the ages.
The terrace outside the observatory has great views over to the Isle of Dogs and Canary Wharf and across to the O2 Arena.
When you are finished with Greenwich Park, head down to the Cutty Sark, a fully restored tea clipper. On the way you will pass the charming Greenwich Market and numerous places to stop for a bite or a pint.
Just outside the Cutty Sark a Victorian foot tunnel takes you across the river to the redeveloped Isle of Dogs. A walk down to the muddy river edge is rewarded with a magnificent view across the Thames to Wrens Old Royal Naval College.
When you have finished with the view, take a Docklands Light Railway train from the wonderfully named Mudchute station to Tower Hill. This elevated railway runs through the heart of the new business district commonly referred to as Docklands with great views of the redeveloped docks of the original Isle of Dogs.
The trains are driverless so the front seats are the best seats in the house but you might have to be quick to get them.
If you have time, stop at Canary Wharf for a look around. The basement and lower levels are taken up by a shopping mall, while above ground there are plenty of eating and drinking establishments. The modern skscraper architecture is quite spectacular.
The last stop at Tower Hill, brings you back to the edge of the City of London next to the Tower, Tower Bridge and St Katherine Dock.