  In this paper we study a static cyclic symmetric traversable wormhole in
$(2+1)-$dimensional gravity coupled to nonlinear electrodynamics in anti-de
Sitter spacetime. The solution is characterized by three parameters: mass $M$,
cosmological constant $\Lambda$ and one electromagnetic parameter,
$q_{\alpha}$. The causality of this spacetime is studied, determining its
maximal extension and constructing then the corresponding Kruskal-Szekeres and
Penrose diagrams. The quasinormal modes (QNMs) that result from considering a
massive scalar test field in the wormhole background are determined by solving
in exact form the Klein-Gordon equation; the effective potential resembles the
one of a harmonic oscillator shifted from its equilibrium position and,
consequently, the QNMs have a pure point spectrum.
