No, it isn’t near Lewes, but this is an extraordinary walk.
I went to school within sight and smell of the Thames at Greenwich and I’ve always thought that it was the tidal Thames that was most worth exploring. I wanted to walk from my home area down to the sea. This is the working Thames, the warlike Thames, the Thames that gave London much of its history. Always grand, sometimes frightening, often lonely, this is one of the wildest areas of south-east England.
The Thames Path National Trail ends rather prissily at the Thames barrier. But on this site you can find out a walk along the banks of the Thames in Kent, one of the most unknown and amazing walks in South-East England. You can also find a description of a link along the Thames from the Thames Barrier to the start of the Kentish Thames walk- a sort of prequel.
Update 2/2/22- The English Coast path has recently opened over this whole area. In many places it takes the same route as the Kentish Thames Walk, but at the time of writing there is no guide to it. It is also likely to miss out some of the places of interest on the Kentish Thames Walk. By all means follow the English Coast Path signs though, if you wish. You will generally end up at the same places!
If you want to go further, you can walk the first four sections and then join the Saxon Shore Way at High Halstow to continue round the coast of Kent.
The Kentish Thames Walk is not waymarked but it is all on rights of way.
It can be done as a long distance walk, on its own as a walk of about 36 miles, or as a grande finale to a walk from the source of the Thames, or in manageable day trip segments of between 7 and 10 miles.
Each stage starts and finishes at a railway station or a bus stop with a frequent service, so the walk can be done as a series of day trips with easy access to London or most of Kent. However buses to the Hoo peninsula do not run on Sundays or bank holidays. Buses to Cliffe, High Halstow and All Hallows run to Rochester and Chatham, not Gravesend. Full details here
This is not really a tourist area, so many hotels are designed for overnight stays for those using major roads and on their way to somewhere else. There are clusters of hotels in Dartford, Gravesend and Chatham. You can find them on www.booking.com Have a look at the location and the reviews. Many hotels are out of town near the motorways and therefore not very convenient, although there are a cluster near the Dartford river crossing that could be useful. Some of the town centre accommodation gets poor reviews, so be selective.
Orchard Cottage in Cliffe Woods, a couple of bus stops away from Cliffe, gets consistently good reviews.
You could hire a caravan at the Haven Holidays site in All Hallows. Outside of the school holidays prices can be very affordable and the minimum stay is 3 days. You would have some distance to travel during the earlier walks.
Do let me know your experiences on this walk at firstname.lastname@example.org