...that look like they're just begging to be adapted, recreated, or otherwise done up in pyramids. If nothing else, it's also a great resource for board ideas. They're unknown because the owner of the page doesn't have rules for them, not because they're archeological finds or anything; I think most or all of them probably have entries at BoardGameGeek.
Some of the ones that make my designing fingers itch are Anti-Grid, Glik/Glak, Celestian, and Jangala. I really like Glik/Glak's modular board idea.