Bothies (mountain huts)

Cwm Dulyn Bothy in the Carneddau Mountains of Snowdonia, Wales (Photo by Kris Williams)
Cwm Dulyn Bothy in the Carneddau Mountains of Snowdonia, Wales

A network of free stone cabins where you can sleep off the beaten path in the U.K.

Melgarve Bothy in the Cairngorn Moutains of the Scottish Highlands
A rustic bothy in Abriachan, above the westnern end of Loch Ness in Scotland
A bothy by Loch Nevis at Kylesmorar

A bothy is a very simple cabin, usually stone, and often in an isolated place—picture it like camping in a stone tent. (Most originally served as accommodation for itinerant farm workers.)

Prepare for you bothy to consosts of a single bare stone room with wooden bunks (some are even bunkless; you sleep on the floor), no bathroom, and no linens provided (though sometimes there's a cold water tap and/or a fireplace or heater).

A few bothies are practually cosy cottages with heat, electricity, running hot water, and bathrooms.

Come prepared as you would for camping—and expect it to be a bit cold (especially as many are in the hills).

The vast majority of bothies are in Scotland and Wales, though there are a dozen or so in Northern England as well.

Most bothies are free, maintained by the Mountain Bothies Association. You cannot reserve one; just find it on the map and show up. There might already be people in it, so you may have to share. 

Some of the nicer ones (like those administered by the Landmark Trust) rent for anywhere from £20 to £60 per night, sometimes with a 3-night minimum, and those are bookable.

You might also look into camping barns and bunkhouses—sort of like rural hostels, with a few more facilities (though they do cost).