What a cock up

All set for a blast down the river this morning, but as we're going down the locks a BW chap comes along asking if we're booked to go on the river? Didn't know we had to says I. Apparently in winter season you have to book a passage through the river locks. So BW chap gives us the number to ring. I ring the number and in true BW fashion I get an answer machine and another number to ring and then another answer machine. So I leave a message stating name, number and where we are, thinking the chap on the other end just might be busy! well you never know.
We waited in the the lock a while then set off down the river. About 15 minutes later we're approching the lock, there's another boat waiting on the moorings, as we get closer we see the crew all fishing and waving at us to go back, I don't think so! On pulling along side, it's a Canal Time boat waiting to go through the lock. They tell us they have to wait two days, the locks closed. So the first photo of the day is Achilles going back up the locks to Stourport.
Plan "B". We'll go up Stourbridge and the Delph spend some time at the Black Contry Museum. So today we just re-traced our steps and had an early stop at Kinver.
But on the way I spotted one or two things that puzzled me, first, why would they build stone steps into a wall you can walk round?

When they cut through the rock why did they leave the little lump on the right?

And what's the hole for, looking at the opening it used to have a door frame set in it. Inside it opens up into quite a large room. It 's on the off side with only foot access.