After the rain, the opuntia cactus, or “prickly pear,” ripens to provide a sweet but not easily accessible meal for animals such as the ground squirrel. As the water seeps in, the park enjoys a moment of relaxation.

The saguaro cactus blooms overnight and its flower is visited the next morning by a Gila woodpecker. As the heat of day rises, harvester ants work go about their work, wary of a mortal enemy in the park.

The University of Cambridge is one of England's greatest universities. There's no main campus – instead, the university's many colleges are scattered throughout the charming town center. Many colleges welcome the public to browse around.