The Battle of Trafalgar
On 21 October 1805, the Royal Navy under Admiral Nelson defeated the combined French and Spanish fleets off Cape Trafalgar -- decisively confirming British naval supremacy.
From the source
Zeeslag voor de kust van Kaap Trafalgar (Spanje), 21 oktober 1805, waarin de Britse vloot onder Nelson de Frans-Spaanse vloot versloeg.
Editorial reading
The battle was fought at sea off Cabo Trafalgar, in the province of Cadiz, Andalusia, Spain, so no single land battlefield site exists. On the Spanish coast, the Faro de Trafalgar lighthouse (built 1860) was, as of March 2025, under review for Bien de Interes Cultural status, a process not yet completed. In Gibraltar, Trafalgar Cemetery (heritage reference HLMP2/023) holds the graves of two confirmed Trafalgar casualties. The Trafalgar Monument in Portsmouth, England, has held Grade II listed status since 1972, but stands far from the battle site itself. No UNESCO World Heritage status has been found for any Trafalgar-related location.
Recommendation
A naval battle with no single physical battlefield, but three related heritage sites in three countries -- Spain, Gibraltar, and England -- each preserving a different part of its memory.