This video, titled Machi Blockbuilder Super Stone Dealer 2" (間知ブロック積み工スーパー石屋2), was released by "koronero2."

You can see stacked blocks when you walk along roads and rivers.
They've been used since the early 1950's as a substitute for natural stone blocks.

Compared to other construction methods, it is cheaper and JIS-compliant, and it is also used for disaster recovery work.

Machi-Blocks are smooth and shaped like a sake cup, which makes them easy to use in curved areas.
There are several ways of stacking machi-blocks, but stacking them to create valley formations is the most common.
One of the upsides of machi-blocks is that they can be stacked in different ways.