In Greek mythology the “wandering rocks”, between which the sea was mercilessly violent. Only Argo was said to have successfully passed the rocks.
A insula is an island (islands), an isolated land area (or group of such areas) surrounded by, or nearly surrounded by, a liquid area (sea or lake). On Titan they are named after islands from legends and myths.
Image Source. Marker locations are approximate and may not always appear to align with image on map.