Stacking Landscape Timber To Make A Garden

Not sure where I came across this photo of a garden where someone used what looks like landscaping timbers.  

Even though this looks like a stock photo it still has some good ideas.

• Like a lot of raised bed gardens that use multiple layers of stacked wood, the joints are alternating.
• I'm assuming there is some type of post or metal rod, possibly rebar, that pins the corners together.
• It looks to be about a foot high
• This makes it good for planting deeper rooted vegetables like carrots an turnips
• Similar to other photos I've seen, the area around the beds is covered with mulch.