Dear Comrades,
You are neglacting the fact that the Legion escaped the Tain in the Great War, and from which where Murgeon and others whom were not of dwarven blood. Hence, it is not true that:
"who built the Tain, were Dwarves, and made it so only Dwarves could escape from"
Yet another question arises. If the Tain was ment to contain the dreaded enemies of Connacht, why then is the place inhabited by spiders? Perhaps the Dwarves had a voice within the creation of such a device for dual-puposes?