Now standing as a splendid ruin on a small peninsula along the marshy banks of Loch Awe, Kilchurn Castle represents 250 years of building, and a similar period of desertion. Originally built as a five storey Tower House, that still survives, largely intact, at the eastern end of the site, Kilchurn Castle was remodelled many times throughout its history.

Sir Colin Campbell of Glenorchy first erected the Tower House c1420 and, unlike many English castles where access was often at first floor level, Kilchurn Castle was entered from the ground floor. Directly above the vaulted entrance would have been the Great Hall, with two further storeys above providing the various accommodation requirements of the castle and, at the top, a garret leading onto a parapet walk. A curtain (Barmkin) wall would have enclosed the remainder of the site, the southern section of which still survives.

At the turn of the 16th century Kilchurn Castle was extended by Sir Duncan Campbell with the addition of a single storey dining hall built along the inside of the south curtain. During the second half of the century, another Sir Colin Campbell, the 6th Laird, continued to improve the castle's accommodation by adding some chambers to the north of the Tower House, and remodelling the parapet. This included the introduction of the circular corner turrets adorned by corbels, most of which have survived remarkably well.