sempiternal

sempiternal \sem-pih-TUR-nuhl\, adjective:

Of never ending duration; having beginning but no end; everlasting; endless.

In all the works on view, Mariani conjures a sempiternal realm that exists parallel to mundane reality and which is accessible through art, reverie and the imagination.
-- Gerard Mccarthy, "Carlo Maria Mariani at Hackett-Freedman", Art in America, September 1999

This is a sempiternal truth for institutions of high prestige. Someone will pay (almost) anything for Ivy-ish credentials.
-- Dennis O'Brien, "A 'Necessary' of Modern Life?", Commonweal, March 28, 1997

Finally, Syon's orchards are the world as our imagination would like it to be -- not wilderness, since orchards are after all planted and cultivated by farmers, but a sempiternal and ideal region of the mind.
-- Thomas L. Jeffers, "That which sustains us", Commentary, June 2002

Sempiternal comes from Medieval Latin sempiternalis, from Latin sempiternus, a contraction of semperaeternus, from semper, "always" + aeternus, "eternal."