In this sheltered corner of Carmarthenshire, in this "timeless, beautiful, barmy (in both spellings) town, in this far forgetful, important place of herons, castle, churchyard, gulls and ghosts", Thomas wrote or re-wrote some of his most admired poems, and found his inspiration for Under Milk Wood.
The house, bought for him in 1949 by one of his many benefactors, Margaret Taylor, wife of AJP Taylor, stands directly below a block of sheer sandstone cliff, a short distance from the small town of Laugharne (pronounced "Larne").
An attractive three-storey building, once two fishermen's cottages, and now run by Carmarthen District Council, it has a matchless view across the estuary of the River Taf, which at high tide laps gently against the cottage walls, and at low tide reveals a fine curve of mud flats.
Thomas in fact chose to write nearby, in a converted wooden garage (his "water and tree room on the cliff") where, after the regular liquid lunch in Brown's Hotel, he would work between 2.00pm and 7.00pm, surrounded by pictures of fellow writers such as Auden, Lawrence, Whitman, Edith Sitwell and Marianne Moore.
Here he created the wonderful, Hopkinsesque "Over Sir John's Hill" (which he could see from his writing shed) and "Poem on his Birthday" ("In his house on stilts high among beaksAnd palavers of birds"), as well as other deeply-felt late poems such as "In Country Sleep".
The inside of the shed, left in a state of Thomasesque untidiness, can only be glimpsed through the window. The Boat House, however, is directly accessible although only the parlour, with views of the water on all three sides, is much as it used to be when the family lived there.
Described by the poet as "very lower-middle-class", the room has family photos on the wall, a 1940s radio set, and some recovered items of family furniture (Caitlin's bright rugs are gone). The desk originally belonged to Dylan's father, that cold and overbearing man who, as an English teacher at Swansea Grammar School, despaired of his apparently wastrel son.
The living-room contains the family's splendid Welsh dresser, but is now a tearoom. The upstairs bedrooms are used for an exhibition about Thomas's life, including some helpful display panels and photographs, English and foreign editions of his work, and an informative video about his time in Laugharne. All is well maintained; but only the views are truly authentic.
As Paul Ferris notes in his acute and insightful biography of the poet, the name Dylan means "sea" in Welsh. There's no doubting the appeal of the coast to Thomas: in addition to a short spell at New Quay in Pembrokeshire, he and Caitlin had already lived in Laugharne before the war.
Their two houses can still be seen in the town. In 1938 the couple set up as newlyweds in a fisherman's cottage in Gosport Street, but soon moved to a larger house near the castle, where Thomas shared a writing gazebo with his novelist friend Richard Hughes. It was during this time that he completed Portrait of the Artist as a Young Dog.
Laugharne was evidently the principal model for Llareggub in Under Milk Wood. Lorraine Scourfield, a local woman who runs the Boat House, says everyone knows who Polly Garter was based on. "She died two years ago, but there's still family around, so we don't tell," she says, with a smile.
The Boat House, Dylan's Walk, Laugharne, Dyfed SA33 4SD. Tel: 01994 427420. Education pack available from Camarthen District Council. Tel: 01267 234567 ext 221. Dylan Thomas, by Paul Ferris, Penguin, Pounds 8.99