I have always been a fan of raised beds in the garden. Aside from the advantages for the plants, I find it easier to organise the garden with raised beds.
In Europe, I used a narrow type of concrete blocks to make the beds. This has two additional advantages: they don't rot (compared to wood), and the soil temperature is somewhat higher with stone. There are disadvantages as well, of course: stone is more permanent and more costly in the short term. I also had raised beds of recycled cobblestones. The image below is such a raised bed I made for someone who afterwards didn't care anymore (
). In those beds, I sometimes left out a stone and planted a herb or lavender, to mimic the effect of a plant growing out of the rocks.
The "construction" is sturdier than it looks