large interlocking basalt columns at the giant's causeway on the north antrim coast of norther ireland

antrim attraction basalt beauty belfast bushmills causeway clochaiexcl aifir coast coastal coastline column destination europe fissure formation formations geological geology geoscience getaway giant giants heritage hexagon hike ireland landmark landscape legend natural wonder nature north northern outdoor rock seascape sightseeing stone summer tourism tourist travel trek unesco united kingdom visitor volcanic