The Bell's Hollow by Hans Christian Andersen

"Ding-dong! ding-dong! " sounded from the buried bell in Odensee river. What sort of a river is that? Every child in the town of Odensee knows it. It flows round the foot of the gardens, from the locks to the water-mill, away under the wooden bridges. In the river grow yellow water-lilies, brown feather-like reeds, and the soft velvet-like bulrushes, so high and so large. Old, split willow trees, bent and twisted, hang far over the water by the side of the monks' meadows and the bleaching greens; but a little above is garden after garden -- the one very different from the other; some with beautiful flowers and arbours, clean and in prim array, like dolls' villages; some only filled with cabbages; while in others there are no attempts at a garden to be seen at all, only great elder trees stretching themselves out, and hanging over the running water, which here and there is deeper than an oar can fathom.

Opposite to the nunnery is the deepest part. It is called "The Bell's Hollow," and there dwells the merman. He sleeps by day when the sun shines through the water, but comes forth on the clear starry nights, and by moonlight. He is very old. Grandmothers have heard of him from their grandmothers. They said he lived a lonely life, and had scarcely any one to speak to except the large old church bell. Once upon a time it hung up in the steeple of the church; but now there is no trace either of the steeple or the church, which was then called Saint Albani.