Snowdon Railway's railway sleepers

Many thanks for the photo. A skillfully built barrier wall, with railway sleepers slotted into RSJ sections. Excellently constructed. Cementing vertically placed steel H frames (RSJ's) into the ground, and sliding the sleepers into them, is a great way of constructing a retaining or barrier wall. Once you have the vertical steel posts in place, it is fast work and has the benefit of the railway sleepers being easily replaced in the future, should the need arise. 

Some might say that the finished look is quite industrial, and so obviously more suitable for a railway or factory, than a domestic garden. But others would argue, especially looking at your meticulously crafted railway sleeper wall, that the finished look would enhance many a landscaping project.