The remains of this burial chamber are just south of Bristol Airport. The mound is almost gone. The cover slab remains - with a hollow in it that collects the rain water, hence the name. The slab is said to always have water in it, and this was taken advantage of by the Wimblestone, who once came to drink here. It's also said (R Tongue - 'Somerset Folklore' 1965) that offerings of primroses and milk were once made here.
A mile or so to the west is Goblin Combe - definite proof of the area's general otherworldly credentials, don't you think. Goblin Combe has a folktale involving primroses too.
There was a parcel of children and they was a-picking primroses, see, and one poor little dear her wandered away on her lone self right down into Goblin Combe. She were only a little trot, see, and didn't know no better. Well, when she do find she's a lost she cries, and the tears do run down her dear little face, and dap on her pinafore like summer rain, and she do throw her self against a rock. Then the rock opens and there's the fairises all come to comfort her tears. They do give her a gold ball and they lead the dear little soul safe home - on account she was carrying primroses, see.
Well, twas the wonder of the village and the conjuror he gets the notion he'd aget his fistes on more than one gold ball when next the fairises opened the hill. So he do pick a bunch of primroses and he go on up Goblin Combe, and he was glad enough to get in to the rock after all he see and hear on the way up. Well, twasn't the right day, nor the right number of primroses, and he wasn't no dear little soul - so they took him!
From 'Folktales of England' by Briggs and Tongue (1965). It was collected by Ruth Tongue who heard it told in chorus by two old ladies from Clevedon in 1945.
[ST 5006 6439] Burial Chamber [GT]. (1) The Water-stone Dolmen, first described in 1896, comprises the collapsed chamber of a presumed long barrow. The mound was visible but with vague edges, in 1924. There are two fallen uprights with the remains of a third and the cover stone which contains a natural hollow and gives the feature its name. A number of large stones in the garden wall of Cornerpool Farm are said to have come from this site. (2-5)
There are now no traces of a mound and in all other respects the above description is correct. (See GP. AO/65/245/5) Surveyed at 1:2500. (6)