Activate Ba Sing Se's second ability by paying {2}{G} and tapping it, earthbending itself.
Activate Ashnod's Altar by sacrificing Ba Sing Se, adding {C}{C}.
When Ba Sing Se dies, it triggers, returning itself from your graveyard to the battlefield untapped due to Spelunking.
When Ba Sing Se enters, Lotus Cobra triggers, adding {G}.
Repeat.

Infinite LTB

Infinite sacrifice triggers

Infinite death triggers

Infinite landfall triggers

Ba Sing Se

Ashnod's Altar

Lotus Cobra

Spelunking

Activate Ba Sing Se's second ability by paying {2}{G} and tapping it, earthbending itself.
Activate Ashnod's Altar by sacrificing Ba Sing Se, adding {C}{C}.
When Ba Sing Se dies, it triggers, returning itself from your graveyard to the battlefield tapped.
When Ba Sing Se enters, Lotus Cobra and Amulet of Vigor trigger.
Resolve the Lotus Cobra trigger, adding {G}.
Resolve the Amulet of Vigor trigger, untapping Ba Sing Se.
Repeat.

Combos with "Ba Sing Se"