Four days Pre cruise in England

I would stay in a different area of London than where you are staying those seven days after your cruise to learn more about the city if you have never been to London before.
We like to stay in Kensington and Chelsea. Being near a tube station is very helpful.
I have no idea about how to get to Dover as we aren’t cruisers.

Train to Dover. Spend 1st night in London and then travel to Dover. There is lots to see in SE England and in Dover. Canterbury, Hastings, and Dover offer several interesting sites. Save your major London sightseeing for afterwords.

train to Dover Priory station and then taxi to the boat is the way I would choose.

With such a late arrival at Heathrow (2 pm will have you leaving the airport around 3:30) leaving you limited chances to get anywhere very far.

I like the suggestion just above to tend southeast, always getting closer to Dover.

If you are still in London when heading to Dover you can use the Southeastern High Speed Javelin service from St Pancras International station which will get you there very quickly. You can also use the Javelin service from Canterbury (East). Otherwise it is the slower traditional trains but perfectly adequate.

What sort of things do you hope to see and do in the time before the boat? Castles? Gardens? Beautiful towns? Historical places? Something else?

Just curious…what cruise line are you taking? The few I’m familiar with use Southampton. Safe travels.

I was going to suggest the same as Carol; Overnight in London and then the train to Dover. You can easily spend a day there sightseeing and it's also an easy train ride to Canterbury for a day. If you're comfortable with driving then the whole SE coast opens up for you. We're doing a driving trip in September and stops include, Dover, Canterbury, Battle, Rye, Beachy Head and Bodium Castle to name a few. I'd suggest possibly saving Oxford as a day trip after your cruise.

The only problem I see with basing in Dover instead of going there to get on the boat (and visit the fabulous Dover Castle) is that Dover is a class A dump. It has been a few years but the experience of the B&B we wound up in in the centre of what passes for the town was an unforgettable experience - and to this day I haven't forgotten it.

Then there is the truck traffic to and from the ferries, and often the trucks take over the main highway A2 as an official parking lot (the infamous Operation Stack). Not for me I'm afraid...

I would also suggest spending the time in and around Dover, but wouldn't stop in Dover itself. Hythe, Deal or Sandwich would probably be nicer...

There's loads to see and do in the area. Dover Castle could easily take a day. Ditto Canterbury. Rye is delightful and could be combined with a trip to Winchelsea.

Take the chance to see something else apart from London!

I would head to Canterbury, which is a much nicer place than Dover. Do a day trip from there to Dover to see the castle and the white cliffs. Leeds Castle is nearby. Whitstable is a charming seaside town with good restaurants, galleries and craft shops.

The local train service is southeasternrailway.co.uk with trains from London Charing Cross, Waterloo East or London Bridge. You can also take the high speed trains from St Pancras, although these are more expensive.

Oxford is in the opposite direction to Kent, so see this post cruise.