B870

This article is about the current B870 in Caithness.
For the former B870 along the north coast from Laxford Bridge to Thurso, see B870 (Laxford Bridge - Thurso).

The B870 follows a meandering U-shaped course around Caithness. The route was originally unclassified, gaining its number later – it first appears on the 1935 OS Ten-mile map.

Route

The route starts at a T junction on the B874 at Glengolly, a short distance to the south of Thurso, and heads southwards along a series of long straights through a patchwork of fields, as a single-track road. There's a long sweeping curve as it goes over the top of a low hill, followed by more long single track straights as it continues south to a staggered crossroads at Mid Calder. A short distance further on, the B870 meets another staggered crossroads, but this time it is the stagger, meaning it has to give way to an unclassified road. Continuing south along two more straights, the route crosses over the Far North Railway Line by the isolated Scotscalder station. So far the route has mostly crossed open farmland. Some is arable, other areas left to grazing, with some of the higher fields only rough grazing. There have been a scattering of houses and farms too, some on the roadside and some down long drives in the midst of the fields.

Westerdale

Beyond the station, a final long straight takes the route over another low undulating hill and down to cross the Burn of Olgrinbeg. It then enters a scattered wooded area, on the flanks of Achlibster Hill, where the road starts to become more winding. The B874 reaches its third TOTSO junction at the tiny settlement of Westerdale, where it turns left to cross the River Thurso on the Bridge of Westerdale. It then continues through patches of forestry and climbs across Achlachan Moss to Mybster, where the A9 is crossed. The route's summit, at 108m, lies just east of the crossroads, as the road detours to the north to avoid Loch Toftingall and Backlass Hill, although both lie some distance from the road.

Once around the low hill, the view opens up to the east across a vast, flat landscape, dipping slightly to the Loch of Watten. The road is once more a long straight single track between wide verges and a patchwork of small square fields. As it slowly loses height, there are a few tight bends to negotiate the last of which turns sharply to the north and so into Watten. This is the largest settlement on the B870, although most of it lies along the A882, which is quickly crossed at a crossroads. The road the dips down to the foot of Loch Watten, enjoying a short S2 section with some large parking areas on either side. Another long straight lifts the road up, crossing over the railway line again, at an uncontrolled level crossing. Watten station used to be here; its platform is still extant.

A short distance beyond the railway, the road reaches Mains of Watten and a T-junction on the B874, which has taken a substantially shorter route to get here than the meandering B870. There's a short multiplex to the right after which the B870 turns left to regain its number and continues northeast for a couple of miles past scattered farms. It's not long, however, before the end of the road is reached, at a T-junction on the B876 alongside a small forestry plantation.