Urza's Tower (5ED) from Fifth Edition, available at 401 Games Canada.

• Rarity: Common
• Finish: Normal
• Artist: Mark Poole
• Card Text:
  T: Add one colorless mana to your mana pool. If you control Urza’s Mine, Urza’s Power Plant, and Urza’s Tower, add three colorless mana to your mana pool instead of one.