If your into the old school Swords of Kos sword and sorcery setting then this one is really a no brainer. This map shows in great detail the world of the campaign and allows a DM to see as well as design their own adventures using the whole cloth of Kos as fodder. This is not our Earth but an alternative world with its own distinctive flavor drawn from the mythology and legends that the designers have come up with.
Kos has plenty of room for a DM to customize and stake out who, what, where they wish to stake out in their own campaign. Everything is laid out in very nice detail within the cartography of Kos and shows all of the locals that the Kos line of products has produced. There's a nice distinctiveness with this map and its a really nice little piece of artistic fluff that allows a DM to pitch their own campaigns within the confines and use this map as both a campaign resource and as a palette to set down their own old world mythological adventures in one sold product.
Maps such as this one can also serve a higher purpose as both a hand out and as reference to give credence to the DM's vision for his or her own campaign. There are several things that I really like about this map. One the colors are not exploding off of the page but reflect Kos's Agean grounding. Second thing is the level of detail is just enough to explain but not over state campaign bits and pieces. The third thing is that there's plenty of room for customization and just enough places to fit a plethora of adventures across the area. Not too bad of a piece of artwork that actually has real world gaming applications.