This heart-shaped formation is an ice cave near Grand Island, Michigan in Lake Superior from 2014. Ice caves like this form when wind and waves push snow and ice into piles. The layers stack up and freeze allowing the formations to grow. Meanwhile, the waves carve out crevices in the mounds, and the spray freezes inside sometimes creating icy stalactites. As the ice and snow melt, and sometimes refreeze, additional formations are created.