The ruins of Aros Castle stand on an easily defensible headland on the north side of the mouth of the Aros River, about 1¼ miles north of Salen. It was built as one of a series of castles intended to control both sides of the Sound of Mull in the 1200s: the best known of these was - and remains - Duart Castle.
The castle seems to have comprised a keep, possibly surrounded by a curtain wall that ran around the top of the 50ft high rocky headland on which the castle stands. Today it takes an act of imagination to see much more than some severely wrecked remains of the keep itself, plus a few pieces of standing stone that might once have been small outbuildings on the landward side.
You get to Aros Castle by taking the minor road east off the A848, just north of its junction at Aros Bridge with the minor road that heads directly north to Dervaig. Signs indicate where parking is possible without obstructing others, and from here you walk the remaining couple of hundred yards to the castle.
A sign near the castle warns visitors that the "owners of castle cannot accept liability for loss/damage or injury to persons or property on land or castle": and it is worth noting that the area of the castle contains sheer drops partially hidden by vegetation, and some less-than-stable stonework.
If you do explore, take great care, and also bear in mind that the area of the castle seems to be a happy home for a healthy population of sheep ticks.
The sheer drops protecting the castle's seaward sides when it was built remain all too obvious today, as does the deep rock-cut ditch intended to defend the castle from its landward side. This would originally have been crossed by a drawbridge.
Aros castle was originally built by the MacDougalls, but it passed to the MacDonalds in the 1300s and during the 1400s was used as an occasional base by the Lords of the Isles, at which time it was known as Dounarwyse Castle.
After the suppression of the Lords of the Isles by James IV in 1493, Aros Castle passed to the Macleans of Duart. When they in turn fell out of favour in the 1600s Aros became a Campbell possession before falling into disuse.