The following description is quoted from [Hals 1750] and must be read in the context of about 1730 when it was written. The extract is taken from [Polsue 1868]. Other extracts are available online.
S. Sennen is situate in the hundred of Penwith, and hath upon the north, S. Just; south, S. Levan; east, Buryan; west, the Land’s End and the Atlantic Ocean. As for the name, if it be compounded of Sen-nan, it signifies, the holy valley; but most likely the name is derived from the tutelar guardian and patron of this church.
At the time of the Norman Conquest this district was taxed under the jurisdiction of Buryan, on which it is still dependent in spirituals as a daughter church. And if this church were extant and endowed at the time of the first Inquisition into the value of Cornish Benefices, 1294, it then was rated also under Buryan. Lastly, this parish was rated to the four shillings per pound Land Tax, 1696, at £57 12s., by the name of Sennan.
Upon view of this church, 1700, the sexton shewed me the headless bodies of some images of human shape cut in alabaster, that were not long before found hid in the walls of the same, all curiously wrought, which also had been painted with gold, vermillion, and blue bice, on several parts of their garments. He also shewed me an inscription on the foot of the font stone, which he told me several bishops of Exeter and their priests, in their triennial visitations at Buryan and this church, had viewed and inspected, but could not read it; whereupon in like manner, I observed on the font stone the said inscription in a barbarous strange character or letters, of which I could see but part, by reason of a new pew or seat was built on a part of it; however, I interpreted that which I saw to consist of these letters, Anno Dom mille CCCCXX or XL, in the year of our Lord 1420 or 1440. Let the curious remove the seat and explain the rest; probably this church was then erected.
At Pen-ros in this parish i.e. the head of the valley, near some high promontory of lands, is the dwelling of Henry Jones, Esq., some time commissioner for the Peace and Taxes, who married Tonkyn of Newlyn
Trevear in this parish, i.e. the great or greater town, is the dwelling of John Ellis, Gent., Attorney-at-Law, who married Davies, and giveth for his armes in a field Argent three eels proper, after the English, out of a supposed allusion to the name Ellis; whereas, ellis, elles, in British, is a son-in-law by the wife; and els, ells, a son-in-law by the husband. And as gealvy is an eel fish in Scotch and Irish, so malsay is an eel in Welsh-British, and sleane is a conger fish in Cornish; and lilly, silly, is an ele or eele, in that language.
This parish affords very little wheat corn, by renson it is a naked country exposed to the wind and sharp air of the sea in winter season, which washes or frets the same out of the ground at that time, unless it stands in the valleys or close places between the hills against the south or east; nevertheless it is abundantly supplied with barley-corn, the soil producing generally, with little husbandry or cultiovation, twenty Cornish bushels in most acres; that is to say, about sixty Winchesters.
In this parish is situate the most remote north-west promontory or headland of the island of Great Britain, where it is not above an arrow’s flight breadth, at the end thereof, the lands naturally or gradually declining from S. Just, and Chapel Carne Braye, four miles distant, to this place, and the sea at least eighty fathom under those places; where, as it were in a low valley, it meets the waves of the Atlantic Sea or West Ocean, and parts some of the Irish Sea and British Channel asunder by its horned promontory of land; which shows that opinion and tradition of the lands further west of old towards Scilly, to be a vulgar error and a fable; for if it had stretched more westerly than it doth in this lower valley, and no higher pitch or degree, the flux and reflux of the sea or tides would inevitably overflow it. Or had there been and considerable parcel of ground there broke off from the insular continent of Britain, (as tradition saith the country of Lionesse was,) by some inundation, earthquake, or accidental concussion, it, must have been much higher land than the contiguous country of the Land’s End is. Otherwise it could not exist there as aforesaid; hut it is not likely there was ever any such land, since no fracture or disjointing of the earth appears on the confines or summit thereof.
Though at low water there is to be seen far off towards Scilly, (probably so called from the abundance of eel or conger fishes taken there, called silleys or lillies,) for a mile or more a, dangerous strag of ragged rocks, amongst which the Atlantic Sea, and the waves of S. George’s and the British Channel meeting, make a dredful bellowing and rumbling noise at half ebb and half flood: which let seamen take notice of, to avoid them.
Of old there was one of these rocks more notable than the rest, which, tradition saith, was ninety feet above the flux and reflux of the sea, with an iron spire at the top thereof, which was overturned or thrown down by a violent storm, 1647, and the rock broken in three pieces. This iron spire, as the additions to Camden’s Britannia inform us, was thought to have been erected there by the Romans, or set up as a trophy there by King Athelstan when he first conquered the Scilly Islands, and was in those Parts; but it is not very probable such a piece of iron in this salt sea and air without being consumed by rust, could endure so long a time. However it is or was, certain I am it commonly was in Cornish, An Marogeth Arvowed, i.e. the armed knight; for what reason I know not, except erected by or in memory of some armed knight; and also carne-an-peul, i e. the spile, spire, pole, or javelin rock. Again remember, silly, lilly, is in Cornish and Armoric language a conger fish or fishes, from whence Scily Islands is probably denominated, as elsewhere noted.
This Place is called by the Welsh bards Pen-ryn-Pen-wid, that is to say Penwith Hill Head Tree, or the hill of the Head Tree, or Penwith Cantred. By the Cornish-Britons, Pedn-an-lase, i.e., the Green Head or Promontary, and by others, Antyer Deueth, the Land’s End.