Starting 24 August, a popup village of builders, programmers, and ecological economists is settling into the Austrian mountains south of Vienna for a month. They are meeting in the Höllental, a valley of steep limestone cliffs and cold rivers, to run the Valley of the Commons: four consecutive weeks, each built around a different theme, commons economics, cosmo-local production, community living, governance and funding, tested against each other in the same physical place rather than argued about in the abstract.