From the announcement:
The Small World Universe is expanding beyond its borders with Small World Realms, a big new expansion that features scores of puzzle-like geomorphic Terrain tiles that assemble into countless different board maps. With Realms, the very ground your fantasy races walk upon is shifting under their feet!
These new maps serve as the battlegrounds for a dozen different preset Scenarios created by the game’s designer, Philippe Keyaerts. You’ll find Scenarios appropriate for both Small World novices and Small World Underground veterans alike, with most of them customized for a varying number of players and many scaling well for up to 6 players!