My husband, 19 yr old son, and I will be in London for four days over July 7-10. My son did a school project on Dover Castle and the tunnels and we want to take one of our London days to visit. I have been to both the castle and tunnels, but it was 30 years ago! I am aware that other than the Castle, tunnels, cliffs, and light house that Dover doesn't have much else to offer. I have found two different touring companies that combine a visit with Canterbury, they're reasonably priced with good reviews, but I don't think we would have much control over our itinerary and in some of the reviews people mentioned missing the tunnels. I've been doing research on just taking the fast train from St Pancras to Dover Priory, I still need to do some research on getting from the station to the castle, I do know the walk is very uphill. Not sure if Uber is an option in Dover? It probably wouldn't take up our entire day, but we could come back to do something else in London that evening. I am open to any suggestions, criticism, or advice for this plan, thank you in advance!!!
Here is info from their website. There is a bus from Dover Priory to the Castle. https://www.english-heritage.org.uk/visit/places/dover-castle/plan-your-visit/directions/
and Dover and Canterbury are served by a train link. Both Canterbury stations are close to the Cathedral.
That bus, the #81, runs every half hour - alternately to Deal or Sandwich.
Note that it leaves from Pencester Road Bus Station (across the road from the Railway station), not from the station itself.
For best value buy a Dover Plus bus ticket with your train ticket- £5 or £3.30 with any National Railcard, unlimited buses in Dover that day.
On the bus the fare is £3 each way, or £6.30 for a Dover Dayrider.