The word 'Enlightenment' comes from the Latin prefix 'en' meaning 'in, or into', and the word 'lux' meaning 'light', so : 

In The Light.

In a spiritual context the concept of The Light is often used to signify The Divine Light of Eternal Truth.

True Enlightenment is said to be infinitely 'beyond' the temporary inner reality of the individual self. 

Beyond imagining. Beyond all ideas, beliefs. Beyond all temporary experiences. 

Words that are used to describe being one with The Light include... 

Unconditional Love, Eternal, Absolute, Infinite.

It is said...

Enlightenment is the moment when the last veil - the last vestige of the fog of self - is burned away by The Truth of The Light.

In that moment it is realised that one's inner reality was only ever the reality known from within the fog.

And in that realisation, the destination of the Inner Journey of the individual self is revealed - in The Eternal Light.