They're self-made. I took a few WIP pics of the construction so I can possibly post a how-to at some point.
Please do! Always looking for new ideas for stone walls and such, and yours do look good.
Wirelizard,
Those really look like some high status Hawaiian (Ali'i) compounds that I worked on at Honaunau on the Big Island a few years back. Right down to the petroglyphs.
LB
Not my work, they're Dolmot's, I just quoted his photo in my reply. Although I agree, they do remind me of the Hawaiian temple we visited in Oahu last year.