Rugged land extending above sea level is most accurately described as a mountain range.

Here's why:

* Rugged: This implies a rough, uneven, and often rocky terrain.

* Land: This indicates a solid, non-aquatic surface.

* Extending above sea level: This signifies that the land is elevated above the water's surface.

While other landforms like plateaus, hills, or even isolated mountains can have rugged terrain, the term "mountain range" encompasses the idea of a series of connected, rugged elevations rising significantly above sea level.