The river Dart flows from Dartmoor to the southern shore and meets the sea at
Dartmouth (got it? Plymouth is at the mouth of the river Plym,
not down the road from Ann Arbor) in Devon.

where there is yet another castle/fort (they must felt really
insecure on the southern flank, or just in general, given
the number of castles and forts everywhere) . . . .

That's all 17 pages of southwest England folks!

Cheers,

--
sugih

P.S. If for some reason you want to see the whole thing again . . . .