You might not stumble on this grotto and mound of earth if you were not looking for it. A seemingly organic swell of land rises from the earth, furred with long rustling grasses and dotted with stones brought over from Ireland. A tunnel through the mound of earth speaks to the suffering of the Irish people during the great famine.
But even without this poignant significance, this would be a beautiful spot to sit and to discover. This would not make most NYC museum or park guides - try to make a special trip to Battery Park City and steal a moment of deep peace.