Letters that make untraversable
s, a, b, e, l, n, r, t, u, v are letters that make 'untraversable'
Words within untraversable
ER, trave, AB, ab, rave, NT, SA, UN, raver, sable, able, traversable, RA, Ra, LE, Er, Ab, Av, aver are words within 'untraversable'