The abyss, the German Abgrund, is a recurring concept and motif which Paul Celan addresses in both his poetics and poetry. The abyss-like quality of Celanís poetry did not emerge unheralded, but the Abgrund topos has been little researched. This paper argues that in Celan Abgrund functions as both a thematic image and textual practice. The Abgrund topos is motivated by rich allusions to Celanís literary sources. Celanís abysses have a paradoxical twofold function. On the one hand the abyss is an ultimate end-point in which significance and value are doomed to collapse; on the other hand, building on that non-foundation is the source of Celanís poetic craft.