The B8025 snakes down the Argyll coast from Kilmartin to the remote settlement of Keillmore on a long, sparsely populated peninsula to the west of Knapdale (northern Kintyre). The road was originally unclassified but had gained its number by 1932.
We start in Kilmartin, world-famous for its archaeological sites, and pass several of them (the Largie Cairns, Temple Wood stone circle, and a number of standing stones) in the neighbouring fields before we cross the Kilmartin Burn. The road then continues almost dead-straight SSW for the next 3.5 km through an area of forestry and across the low-lying Mòine Mhòr to reach Islandadd Bridge at the mouth of the River Add. The marshy nature of this section of the route is underlined by the presence of "Weak Road" signs.
After crossing the Add and then the Crinan Canal – the latter via a narrow and weight-restricted (3 t) swing bridge – we immediately meet the B841, which runs alongside the canal. Turning right to follow the latter road for 450 m, we fork left beyond Bellanoch, leaving the B841 to continue north-westward to Crinan itself. The B8025 immediately starts climbing, with a very long dead-end leading to the village of Kilmory turning off to the left near the summit. We continue south-westward, doubling back down the hill, before reaching the shore of Caol Scotnish (a sea loch), almost completely hidden by forestry.
It is several miles before we reach Tayvallich, the only real village on the peninsula, and navigate around its pretty harbour. Then we climb another hill out of the village and run along the long finger of land with views across to Taynish. A final turning sees another road turn east to New Ulva, and across a causeway to an island, while the B8025 finally reaches Keillmore. Maps show that the road continues through a couple of gates to end at the pier. It is worth stopping in the little car park through the first gate and walking up to the old Keils chapel on the hillside, which not only affords excellent views, but is also home to a collection of medieval carved grave slabs, similar to those found at Kilmartin and Kilmory.