Built in the late 18th century by Archibald Fraser, Boleskine House would have likely remained a pleasant but unremarkable property on the banks of Loch Ness had it not been chosen by The Great Beast as a haunt from which to summon demons. The resident in question is, of course, Aliester Crowley. He occupied the pile from 1899 - 1913.
He claimed to have chosen the building for several reasons, though it's not clear how many of them are a product of Crowley's overactive imagination. He considered its architecture and layout to be favourable to the summoning of spirits. It fulfilled the need for a building with "...a door opening to the north from the room of which you
make your oratory. Outside this door, you construct a terrace covered
with fine river sand. This ends in a "lodge" where the spirits may
congregate." Thus Crowley felt that the building occupied some special place in the cosmic order; he considered the "Magical East" of certain systems to be somewhere around Boleskine. There are even rumours of a secret tunnel linking Boleskin house to a nearby graveyard close to the waters of Loch Ness which was an ideal location for sacred rites. Certainly the secluded site must have offered practical benefits.
Regardless of how many of the colourful myths about Boleskine are true, what is certain is that the building now occupies a special place in our folklore. It was owned from the early 1970s until 1991 by Led Zeppelin guitarist and Aleister Crowley enthusiast, Jimmy Page. In this interview he claims some of the spirits raised by his predecessor still walked the corridors (or, in the case of the severed head, rolled down them).
I was especially excited to discover the floorplan shown below. I find such schematics endlessly fascinating - they are at one abstracted representations of 3D space and a product of how the human mind conceptualises enclosed volumes.
Photos from here, here