One of these is Earl's Knowle. It is the longest chambered cairn in the UK, being 75m east to West by 12m at the West end and 20m at the East, where it attains a height of 2.2m. The Inventory of Monuments in Orkney has this to say:

"As seen today it presents no features by which its true character can be determined, but the Statistical Account speaks of it as having ‘the appearance of old ruins and graves, one of which graves, evidently defined by two stones, one at the head, the other at the feet, is eight feet and a half long; this grave was dug up to the deepness of about six feet, in the month of July 1792; the stones at the head and feet, which appeared about a foot above the surface, reached to the bottom of the grave. Many human bones of an ordinary size were found, and, moreover, fragments of a human skull, and of a lower jaw bone, with the case of teeth, which were perfectly sound, the fragments of thigh bones; these were all of an enormous size, and afforded a convincing proof that the boy buried [sic] there had required a grave of the dimensions above specified.’”
Vol. xv (1795), pp. 418-9. xcii. 15 June 1928 [Historical Monuments (Scotland) Commission, Inventory of Monuments in Orkney, Page 337]

As well as containing other human remains, Earl's Knowle is traditionally thought to be the final resting place of Sir Patrick Spence. The history relating to the burial of Sir Patrick Spens on Earl’s Knowle on Papa Stronsay is related by William Edmonstoune Aytoun (b. Edinburgh 21 June 1813, d. 4 August 1865). He was made Sheriff and Lord Admiral of Orkney and Shetland in 1852. It was after his retirement from this position that he edited a collection of Scottish poetry in which the first poem is Sir Patrick Spens, subsequently made more famous by the poet Coleridge. In his forward to the poem Aytoun writes:

“It is true that the name of Sir Patrick Spens is not mentioned in history; but I am able to state that tradition has preserved it. In the little island of Papa Stronsay, one of the Orcadian group, lying over against Norway, there is a large grave or tumulus, which has been known to the inhabitants, from time immemorial, as ‘The grave of Sir Patrick Spens’. The Scottish ballads were not early current in Orkney, a Scandinavian country; so it is very unlikely that the poem could have originated the name. The people know nothing beyond the traditional appellation of the spot, and they have no legend to tell. Spens is a Scottish, not a Scandinavian name. Is it, then, a forced conjecture, that the shipwreck took place off the iron bound coast of the northern islands, which did not then belong to the Crown of Scotland? ‘Half ower to Aberdour’ signifies nothing more than that the vessel went down half-way between Norway and the port of embarkation.”

The island of Papa Stronsay is said to be about half way between Aberdour in Buchan and the coast of Norway, half owre to Aberdour; and on this island there is a tumulus, which Mr Maidment informs us is known now, and has always been known, as the grave of Sir Patrick Spens.

St. Nicholas’s Chapel dates from the 11th century. Originally a simple rectangular church, it was extended in the 12th century when a chancel was added, resulting in a more complex design comprising a nave, with two side altars, and a chancel containing the main altar. The chapel was abandoned in the 16th century, but was reused as an agricultural building until around 1790 when it was partially demolished to provide building stone for a barn. By the 1990s there was nothing to see of the church except for a few bumps in the turf.

In 1998 excavations were begun and the ruins of the chapel described above were unearthed. However, underneath the remains of the11th/12th century church were found those of a much earlier building, which from its style was dated at 8th century. From the lack of domestic debris found around it, as well as the fact that the 11th century church was built directly on top of it, it is thought that this building is the remains of the original Pictish church. The official website of the dig continued:

"The possible earlier church is by no means all we have found in the first two seasons of excavation.  Towards the end of our excavations last year we uncovered further curvilinear buildings on the periphery of the 11th/12th century chapel but clearly earlier than it in date.  This time the buildings did produce midden material – animal bones, shells and broken pottery – suggesting domestic dwellings.  But are these buildings just part of an ordinary Iron Age settlement which pre-dated the Norse church or are they – a much more exciting possibility – the cells of a Pictish monastery, where the monks lived who worshipped in the putative Pictish church underlying the later medieval one?……And there is yet more evidence of an earlier stratum of Christianity pre-dating the medieval church, for around this later church we have found not one set of churchyard walls but two.  One set of walls seems to belong with the later church but the other is earlier.  Could these be the walls surrounding the churchyard of the Pictish church?"...

...“A remarkable find from eastern Europe. It is more than just the absence of domestic debris that makes us think we may have uncovered a Pictish church.  One find from within the building is of special significance.  It is a small piece of green porphyry, a polished stone which displays pale green crystals against a dark green groundmass.  The stone comes from Greece and was widely used in Roman Imperial times to decorate baths, temples and other prestigious buildings.  So what is it doing in a Pictish building on a tiny remote island of northern Scotland?  Only ten other finds of green porphyry have been made in Scotland.  All but one of these have been found in an ecclesiastical context, and most at sites that are pre-Norse foundations.  It is thought that the porphyry was used to decorate altars, reliquaries and such-like.  So, insignificant though the find may at first seem – just a fragment of stone that an inexperienced excavator may easily overlook – it is another, crucial, piece of evidence suggesting that the building underlying St Nicholas’ Chapel is an earlier church on the same site.”

“Industrial Monuments: 229 Kelp Kilns HY 6622 2961 HY 62 NE 18. This is a rare survival of an ‘improved’ kelp-burning kiln, a relic of an unsuccessful experiment at about the turn of the century. There are two drystone-built “chimneys” 5m apart, one 2m and the other 1,4m high, the latter rising from a stone platform incorporating a fireplace-like opening. The ‘chimneys’ are connected by tunnels. It is not clear how this arrangement was intended to work. July 1979. Thomson 1983, pl. opp. pg.97; OR172.” [From Lamb, Sites and Monuments of Eday and Stronsay ]

“James Chalmers was living on the Island of Papa Stronsay around 1900. He lived with his wife and family in Stackaback, and was designated in the 1901 census as being a ‘kelp maker’. He was a man who was reputed to be skilled with his hands and obviously had a fairly active mind as well. He had probably worked at kelp making for a number of years, and would have understood the problems of getting seaweed dry enough to burn. He therefore decided to build two kilns for the purpose of drying and burning kelp. It is said that he intended to burn one kiln, and the heat from that burning would dry the next one ready to burn. It is difficult to imagine how he could have transferred the heat from one kiln to the other without some form of mechanical blower. On the other hand he could have had some form of mesh cover that he put across the top of the kiln to take a load of seaweed, and the heat from the burning below would dry the seaweed, which would then be placed in the second kiln to burn, while the first kiln was cooling. This is all speculation, and is really quite irrelevant as he soon came up against a much bigger problem. At this point it is necessary to understand the basic workings of a furnace. For his furnace bars, he decided to use the bars out of a steam ship which are made of cast iron, and this material is quite capable of being melted in the heat of the furnace. To prevent this, the fire must be kept clear of ash and clinker at all times, so that the draught of air going up keeps the bars cool. However when seaweed is burnt it is extremely hot, and settles together in one molten mass through which very little draught would flow. Consequently he melted all his furnace bars, and could get nothing to replace them. About this time the kelp industry was in fast decline, so this was the end of the experiment, and the two kilns stand today just north of the Watermill.” [Mr. Ralph Fotheringhame descendant of the above mentioned James Chalmers.]

In the 19th and early 20th centuries, Papa Stronsay became a centre for the herring industry in Orkney. W. M. Gibson writes in Vol. 1 of his book "The Herring Fishing, Stronsay":

"By 1927 Stronsay's contribution to Orcadian rates was considerable: at a yearly figure of 7,828 pounds it was the highest parish figure. This was raised form quite an extensive industrial complex for such a small island. In Whitehall village there were 19 curing stations and three piers; offices for 23 fish merchants and others; 2 curing stations; 1 red herring house; 16 shops; a police station and a cinema. On nearby Papa Stronsay there were 5 curing stations, accommodation for the gutters and various small piers."

Mr. William Miller of Stronsay, writting of Papa Stronsay says:

The following photos were kindly given to us by Nan Scott of Kirkwall.