20 Euros Demänovská Cave of Liberty

Demänovská Cave of Liberty sits within the Nízke Tatry mountains and was opened to the public in 1921, exactly a century before this coin's issue — the centennial timing drove the entire commemorative program. The cave system connects underground with Demänovská Ice Cave, though the two have been managed separately since their tourism development in the early twentieth century.

Slovakia has issued silver twenties honoring natural and cultural heritage sites with some regularity since independence, but cave subjects are genuinely rare across European commemorative programs generally.