Bridge over the River ?

"Greta" derives from the Old Norse "Griótá", meaning "stony stream". And it it.
That said, most lakeland becks are fairly rocky.

We did intend to nip over to Buttermere for an Ice-cream each. Halfway twixt our pad and North Lakes Hotel Gaffer squeaked "AAaargh, Blood Donors." We had BOTH forgotten, so I popped in to become, literally, the last for the day and donate my 60th "Whole Armful".
In consequence we had to buy the Ice-cream in Keswick, Mango sorbet was Bootiful. Followed by a "bit of a wander" which took us into Fitz Park. I had never noticed before, but there's actually a Flood gate in the wall, must Blip it next time.
BTW I didn't pluck up courage to remove the plaster until Wednesday night. MUST remember to SHAVE a patch of inner elbow next time.