They form a 248 ha site encompassing five small boulder coral islets, on a substrate of submerged reef, which can vary in size and shape following winter storms and hurricanes.

Three of the islets are covered with salt-resistant plants dominated by buttonwood, sea purslane and bay cedar.

[1] Birds for which the IBA was designated include Sandwich, roseate, common, sooty, bridled, least and royal terns, as well as black and brown noddies.

The main nesting season is from early April to mid-August.

The main threat to the nesting birds is predation of eggs and chicks by laughing gulls.