In 2005, Roger Castillo's dog found a bone beside the Guadalupe River. But it wasn't just any bone—it was the skull of a young Columbian mammoth. Paleontologists from UC Berkeley's Museum of Paleontology joined Roger on the scene, where they excavated a thigh bone and the pelvis of the ancient creature. The fossils were assembled into a full-scale replica of the baby mammoth, affectionately named "Lupe," and moved into the Children's Discovery Museum of San Jose. This happy accident became a permanent exhibit—and created a fitting unofficial mascot for an institution celebrating curiosity and wonder.

Today, visitors can stop by the museum's Mammoth Discovery! hall to see Lupe's towering frame, housed alongside 20 other hands-on activities that spark the scientific minds of little visitors. This sense of exploration is at the core of the museum's 150 exhibits. And while it may be a while before kids discover their own extinct animals, the museum's 52,000 square feet help build foundations in math, science, and art. The colorful WaterWays room, for example, uses pulleys and tunnels to teach youngsters about the properties of rivers or flooded bathrooms, while the Rainbow Market helps kids learn more about healthy fruits and veggies. Most exhibits stay on permanent display, but the museum also hosts special exhibits and events throughout the year, such as interactive storytelling performances.