The Achininver Youth Hostel, an old croft that has been preserved,
modernized and turned into a somewhat remote and rugged hostel. It's
not very far up the coast from Ullapool, but is a 25 mile drive (on
single track roads) because there isn't a road that goes up the coast.
And after that 25 mile drive on little roads, there's a 1/2 mile hike
out to the hostel from the road. But it's a beautiful location. The
mountain Ben Mòr Coigach is behind it - Coigach is the name for the
area (A' Còigeach in Gaelic meaning "place of fifths. Land was often
divided into 'fifths' in ancient times.) and Ben Mòr just means 'big
mountain', so it is the 'big mountain of Coigach'.
For anyone interested in the Gaelic origins of place names, a nice book
published by Scottish National Heritage is available for free as a pdf
online:
A' Ghàidhlig air Aghaidh na Tìre / Gaelic in the Landscape.

Advreck Castle on Loch Assynt - the 15th century seat of the MacLeods
of Assynt. During its lifetime it was the scene of considerable
violence. A siege in 1672 ended the MacLeod ownership of Assynt,
after which it was never fully re-occupied. A lightning strike in
1795 largely destroyed it.