Lochranza Castle stands on a low promontory at the edge of the sea loch, accessible by a short walk from the village. The current structure is an L-plan tower house, mostly dating from the 16th century, though there was a fortification here at least two centuries earlier. It is roofless and partly ruined but structurally impressive, with walls rising to several storeys.
Access is free and unrestricted — the castle is in the care of Historic Environment Scotland and has no gate or admission charge. Walk out to the spit of land it occupies for views back toward the village and across the loch to the hills on the west side. On a misty morning the effect is genuinely eerie, with the castle seemingly floating on the water. The walk takes about ten minutes each way from the village centre.