Ohh @MissConductUS ...that is indeed a fantastic area !
Depending on their length of stay ...but I highly recommend the Thames Clipper .
It is like a river bus .
Greenwich is easy to get via it and it is a much more enjoyable way of getting there that by TFL .
Even as a Londoner .. I get excited about going on it 😂.
Hop on hop off ticket might work out cheeper than using contactless thought as there is no daily cap on the fares so each fare is added and along with exchange rates could work out a bit expensive.
Love loved loved Greenwich!
One leg either side of the Meridian Line 😂.
And the Cutty Sak is amazing.
The London Underground Tube can be quick ......
But overground will let you see much more .
In face thinking about it ...
A travel card might be there best bet for travel in London .
Tube ...tap in and out ....even if barrier is open ..
Very important
You will be charged more if you don't tap out ...not less !
Same with over ground train.
Bus...
Only 1 place to tap and that is with the driver and then that is it.
No tap out.
No cash allowed to buy a ticket on the bus.
Happy to answer any other queries !