South Holstein comprises the southernmost part of Schleswig-Holstein forming a horseshoe right north of Hamburg.
This article covers the districts ("Landkreise") of Steinburg, Pinneberg, Segeberg, Stormarn, and the city of Neumünster.
These are the parts of Schleswig-Holstein that don't border the sea, but still you can see big ships sailing on the Elbe or the Kiel Canal, making up the southern and western borders of the region described here. Like the state in general, the region is flat, even partially below the sea level, made up of marshland and farmland. The region doesn't have any world-famous attractions but the cities, towns and villages do have interesting buildings, museums and other things to explore. There are also local events going on through out the year, though the heavy metal music festival Wacken Open Air isn't so local drawing bands and fans from around the world.
Some towns here were once famous for their spas – the bathing is mostly a thing of the past but the "Bad" prefix still remains. Finally, you can always head out to explore local flora and fauna in the natural reserves.
Hamburg airport is the obvious option.
Trains between Hamburg and the rest of the state go through South Holstein. For example trains to the west coast go via Pinneberg and Itzehoe, trains in the direction of Kiel, Flensburg and Denmark go via Neumünster, the ones going in the direction of Lübeck take you to Bad Oldesloe.
Likewise, Autobahns and other roads between Hamburg and the north pass through the area.