A stately pleasure-dome decree:
Where Alph, the sacred river ran
Through caverns measureless to man
Down to the sunless sea.
Coleridge

Next we visit Wookey Hole, a series of limestone caverns, also in Somerset. Here at last I actually find a boat to answer the call of the prompt image.The occupant appears to be standing alongside, perhaps the better to appreciate the scale of his surroundings.
In the next card shows the Escape of the River Axe, but no boat party.
These rather dull sepia cards are enlivened by the a visit to the ‘Witch of Wookey Hole’. Go on, you know you can see her!
"Double, double, toil and trouble
Fire burn and cauldron bubble.”
At last we find an occupant of a cave. This is St.Michael’s Cave in Gibraltar. It’s a so-called Neanderthal Man, who apparently sat out the last Ice Age in these caves. A skull was found in 1848. All he needs now is a Rock Chick and the party can begin.
Ok it’s not that sort of party in the prompt picture. At the end of our cave journey we finally spot a party of people enjoying the Postojna Caves in Slovenia, or as it was then, Yugoslavia. They aren’t in a boat though; this is a train, and the link shows that these are much more modern than the one shown here.
Why not join other troglodytes for this week’s Sepia Saturday? Here’s the prompt: Party in Boat, Speedwell Cavern, Castleton.