Space - the final frontier: Recent progress with metal-organic scaffolds (see picture for an example) to create synthetic ion channels and pores is summarized in this Highlight. The great advantage of this approach is access to a stable and large confined space from small structural units. Current breakthroughs promise future progress toward the synthesis of tubular structures and their multiple functionalization. Recent progress with metal-organic scaffolds (see picture for an example) to create synthetic ion channels and pores is summarized in this Highlight. The great advantage of this approach is access to a stable and large confined space from small structural units. Current breakthroughs promise future progress toward the synthesis of tubular structures and their multiple functionalization.