Undiscovered Paradise

[Rascal]

HI,

how is the right function of Undiscovered Paradise going?
Is it returns every turn on upkeep, or it had has to be used in the turn for mana?

I hear both of explanation and I´m a little bit confused.

THX

[Taurelin]

{T}: Add one mana of any color to your mana pool. During your next untap step, as you untap your permanents, return Undiscovered Paradise to its owner's hand.

The returning of the land is part of the effect of the activated ability. So it only happens if you activated it, i.e. only if you tap it for mana.