Abstract: A free-standing structure having n sides defining n origins where n is greater than two, including a frame having n arch members, two paired arch members fixed at each of n origins; each arch member extending from its origin, across its paired arch member to a different origin across from its initial origin, the arch members forming an n-sided polygon at the top center of the structure; the paired arch members crossing each other on the far side of the polygon relative to the initial origin, the crossing occurring on an axis of symmetry extending through the initial origin and the top center of the structure; and means for securing together the paired arch members at the origins.