This is a castellated miniature fort with circular gun-holes and five battlemented towers situated on one of two islands within the lake.

It would have been constructed just shortly before, or at the same time as, the famous defence by the British of their garrison on Gibraltar against the Spanish during the ‘Great Siege’ of 1779 to 1783. The siege, which lasted nearly three and half years through starvation and repeated onslaughts by the Spanish, was impressive news at the time and must have motivated the naming of the fortress as Gibraltar.

However the fortress at Larchill was much more a source of pleasure and entertainment with stories of mock battles across the lake.