Retaining walls and steps
Railway sleeper and dry stone retaining walls that hold a slope properly, with steps built into them.

A sloping garden is usable ground waiting for someone to hold it back. Sleeper walls, natural stone and dry stone walling all do that, and which one is right depends on the load behind it and what the rest of the garden looks like.
Drainage behind a retaining wall matters as much as the face of it. Water with nowhere to go is what pushes a wall out. Every wall gets backfilled and drained so it stays where it was built.
Retaining walls
More of this work

Sleeper wall and steps into the slope 
Terraced stonework and gravel steps 
Steps built to reach a new patio