ST. KILDA AND ITS BIKftS. 327 



Thai tliis building represents an underground dwelling- 

 place of some of tlie original inhabitants of the island is 

 not improbable, and it is likely enough that other similar 

 structures exist in the island awaiting disinterment by 

 the shovel of the archaeologist. 



On the island of Soay stands a small stone structure, 

 which goes by the name of the " Altar." It is composed 

 of hat stones laid one above the other in regular courses, 

 though those at the top are now very uneven, is of 

 rectangular shape, and measures now about 6 feet by 

 5 feet 8 inches by 3 feet inches in height. The origin of 

 this little structure is lost in hoary antiquity, but it has 

 without doubt been constructed for a definite purpose, and its 

 use was probably that indicated by the name attached to it. 



One other relic of bygone times may be mentioned, 

 namely, the so-called " Fort," near the point of the 

 island of Dun. The extremity of this island-promontory 

 consists in great part of a chaos of rocks and boulders, 

 many of them of prodigious size, which are scattered 

 about in all directions in the wildest confusion. These 

 rocks form a natural fastness, tenanted now by hordes 

 of Puffins and Razor-bills, the comparative security of 

 which had evidently been taken advantage of by the 

 inhabitants in remote ages as a refuge from their 

 enemies. For, on the only vulnerable side of this retreat, 

 a wall has been built leading down the hillside from the 

 rocks above to the cliffs below, which constitutes the so- 

 called " Fort." It is constructed of large flat stones, laid 

 one above the other in more or less uniform courses, and 

 Would doubtless in ancient times have served as an efficient 

 rampart. Secure from any attack on the seaward sides by 

 the unscalable nature of the cliffs, the aborigines of the 

 islands might well have defended themselves here against 

 the incursion of an invading horde. 



