The Spring of Eterna is the only place in Cephiro where the legendary ore Escudo can be found. It was here that the Magic Knights received their own Escudo which was later sculpted into their swords by Presea.
It has a rather peculiar appearance. When looking at the spring from the side, all one will be able to see is a straight blue glowing line. But by viewing it from above, one can see that it is indeed a spring, after which the warrior in question will descend into the spring and gain their Escudo. From the inside, it just seems to be a dark pit.
It is named after the Mitsubishi Eterna.