Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Life from the Loam

Return up to three target land cards from your graveyard to your hand.
Dredge 3 (If you would draw a card, you may mill three cards instead. If you do, return this card from your graveyard to your hand.)

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Spreading Algae

Enchant Swamp
When enchanted land becomes tapped, destroy it.
When Spreading Algae is put into a graveyard from the battlefield, return Spreading Algae to its owner's hand.