The existence of the Upper Lunch Hut implies the existence of a Lower Lunch Hut, but as far as I can tell, no such building exists. It's one of many mysteries that surround the edifice, which I discovered during a holiday in the Cairngorms this August, while everybody else at RPS was writing about some tyrannous entity called Gamescom.
First, the approach: having exited a vast pine forest of primeval aspect and supernatural disposition, with distant, daylit clearings leading the eye deeper and deeper into the undergrowth, till it feels at last as though your gaze has become tangibly enmeshed with clutching root and lowering branch - having finally escaped from that terrible, terrible forest, with its single, mournful stream crossed by a bridge of predatory bareness that is surely a haven for trolls, you set out across a grey and purple oblivion of reed and heather, a moorland rising to the border between glens, broken only by the stark red stain of a door. Nearing this otherworldly aberration, this scarlet phantasm, you realise that there is a house constructed around it, a sloping excrescence of withered planks and flaking plaster. What fell secrets could it harbour? Let us go and make our visit.