Retreat to Coralhelm + Sakura-Tribe Scout + Simic Growth Chamber

Retreat to Coralhelm
Sakura-Tribe Scout
Simic Growth Chamber

Requires
Simic Growth Chamber in hand. All other permanents on the battlefield. Sakura-Tribe Scout does not have summoning sickness.
Steps
  1. Activate Sakura-Tribe Scout by tapping it, putting Simic Growth Chamber from your hand onto the battlefield
  2. Simic Growth Chamber enters the battlefield, triggering itself and Retreat to Coralhelm
  3. Resolve the Simic Growth Chamber trigger, returning itself from the battlefield to your hand
  4. Resolve the Retreat to Coralhelm trigger, untapping Sakura-Tribe Scout
  5. Repeat
Results
Infinite landfall triggers.