The South Aegean is the Greek region covering the Cyclades and Dodecanese island groups, and today Santorini and Mykonos are the two islands Travelog covers: Santorini's guide plus a standalone Akrotiri excavation page, and Mykonos's guide plus a standalone Delos page, the small uninhabited island beside it that actually carries the UNESCO listing.
Santorini and Mykonos are the South Aegean's two most internationally recognized islands, and neither carries a UNESCO listing on its own, a genuine, honestly-disclosed gap from most of this guide's other cities. What each island does have is genuine: Santorini's Akrotiri excavation and Mykonos's neighboring island of Delos, both covered here with their own standalone pages.