Fivefold tunnel is a freestanding arched passageway composed of intersecting sets of parallel steel bars. The bars create a latticework structure whose pattern, based on Amman lines, displays fivefold symmetry. Five sets of parallel lines, spaced according to the golden ratio, cross each other at angles of 108 and 72 degrees, generating a complex aperiodic pattern that defies viewers’ expectations. The use of fivefold symmetry in this work stems from the artist’s close collaboration with Icelandic mathematician and architect Einar Thorsteinn.