Plensa's works include the Crown Fountain at Millennium Park in Chicago, Illinois, which opened in July 2004.
The fountain is composed of a black granite reflecting pool placed between a pair of glass brick towers. The towers are 50 feet (15 m) tall, and they use light-emitting diodes (LEDs) to display digital videos on the inward faces.
In the summer of 2007 he participated in the Chicago Public Art exhibit, Cool Globes: Hot Ideas for a Cooler Planet.
Another Plensa piece is Blake in Gateshead in North East England, a laser beam that on special occasions shines high into the night sky over Gateshead's Baltic Centre for Contemporary Art.