To be informed about so-called dx-peditions, ham's activating special places or special 'commorative' callsigns you can subscribe to newsletters. No doubt there will be more newsletters or sites with info that is of more interest to you
Daily DX
Weekly DX info
World Wide DX Club
eHam net (ARRL nieuws)
 
DX World
The DX Zone
425 DX News
To be informed as quickly as possible or to inform your fellow ham's about interesting or special stations you can use socalled clusters. Check which of those clusters suite you the best, as it is of no use to check several clusters at the same time. Often they present the same information
eHam net dx cluster
QRZ com dx cluster
DXScape cluster
OH8X dx cluster
 
AC6V Packet cluster (Several interesting links)
Ham Radio de Luxe [HB9DRV] dx cluster
VE7CC dx cluster
hamspots.net/wsjt/
A very neat tool to analyse cluster spots can be found at: http://www.dxheat.com
The world has thousands of islands of which many are not inhabited. Some ham's are challenged by ham operation from those islands. Also there are ham's chasing those islands.
Next, there are ham's challenged by the idea of contacting other ham's from the top of a mountain or hill.
And there are ham's operating from within national parks
Information about those operations:
Islands on the Air (IOTA)
Summits on the Air (SOTA)
World Flora and Fauna (WFF)