If you can track down Amano’s Nature Aquarium World Book 2, there are several 55cm cube scapes
Though none are Iwagumi - perhaps related to the height, as there are tall grasses or stems
Closest is titled “crimson leaf finery” which has what appears a rounded mountain rising to a peak in the back left corner, “grassland” curves around this across the full front of the tank and extending to right back corner and behind the first rising “hills” - probably 60% of the footprint is grassy plain, and then then hill which looks to be more than half the tank volume as it rise in height
Actual plants are riccia and Barclaya longifolia red
I’ve long admired this scape for those crimson highlights (Amano uses this plant in a few scapes in this book series, but I’ve never seen this plant for sale (though I believe Tropica did grow this at one time) - though I have purchased plants advertised as such

)
Riccia forms the grasslands as well as climbing the mountain terraces
Photos of this tank are more artistic so it’s difficult to discern actual heights