Fairy fort / earthen ringfort in Mundellihy

Mundellihy in County Limerick holds a hidden thirty-metre ringfort beneath level pasture, visible only as a faint crop mark rather than a solid ridge. The earth swallowed the boundary, yet the shape persisted in the way grass grew or soil drained. People may have lived inside that invisible circle before forgetting its edges, leaving behind a ghostly disk instead of a wall.