For 10 points, name this difficult-to-pronounce analogue of the Hebrides found in Neal Stephenson's Cryptonomicon.
One island in this group has a silhouette consisting of three basaltic columns. Prospective visitors may reach it by passing the Utter Maurby breakwater, but are to be given "detailed vomiting instructions" beforehand. The inhabitants of the Innner island of this name "practically laid out the welcome mat for the Romans" and were transported en masse to (*) Australia, where they became an important immigrant community in Brisbane. Their home was "barely even an island," being connected to the mainland by a tidal sandbar.  Another native of this region who was saved from marauding janissaries is ►  Eliza, who appears in The Baroque Cycle. For 10 points, name this difficult-to-pronounce analogue of the Hebrides found in Neal Stephenson's Cryptonomicon.
One island in this group has a silhouette consisting of three basaltic columns.
Qwghlm (accept any even remotely reasonable attempt to pronounce this; apparently the official pronunciation approximates "Taggum")