Retreat to Coralhelm + Walking Atlas + Golgari Rot Farm

Retreat to Coralhelm
Walking Atlas
Golgari Rot Farm

Requires
Golgari Rot Farm in hand. All other permanents on the battlefield. Walking Atlas does not have summoning sickness.
Steps
  1. Activate Walking Atlas by tapping it, putting Golgari Rot Farm from your hand onto the battlefield
  2. Golgari Rot Farm enters the battlefield, triggering itself and Retreat to Coralhelm
  3. Resolve the Golgari Rot Farm trigger, returning itself from the battlefield to your hand
  4. Resolve the Retreat to Coralhelm trigger, untapping Walking Atlas
  5. Repeat
Results
Infinite landfall triggers.