Play Selesnya Sanctuary. When it enters, Amulet of Vigor, Selesnya Sanctuary and Springheart Nantuko trigger.
Resolve the Amulet of Vigor trigger, untapping Selesnya Sanctuary.
Holding priority, activate Selesnya Sanctuary by tapping it, adding .
Resolve the Selesnya Sanctuary trigger, returning it from the battlefield to your hand.
Resolve the Springheart Nantuko trigger, causing you to pay 1 to create a token copy of Dryad of the Ilysian Grove.
Because of the additional Dryad of the Ilysian Grove token, you can play an additional land this turn.
Repeat.
This clever loop relies on bouncing and replaying Selesnya Sanctuary to endlessly fuel landfall triggers. With Dryad of the Ilysian Grove allowing you to play extra lands and granting them all basic land types, every time Selesnya Sanctuary re-enters, Amulet of Vigor instantly untaps it so you can tap it for mana before its own bounce trigger returns it to your hand. Meanwhile, Springheart Nantuko (bestowed onto a creature or operating as an independent piece) uses those very same land drops to repeatedly pay its landfall cost, flooding the board with infinite creature tokens, enter-the-battlefield triggers, and landfall activations.