There was an unusual sight at Building A of the Faculty of Mathematics and Natural Sciences (FMIPA) at the University of Indonesia (UI) on the morning of Saturday, May 10, 2025. Instead of the usual bustle of university students, the hallways of the Department of Geosciences were filled with the cheerful laughter of 20 children aged 4 to 8 from Hayya Playspace. They weren’t just there for a visit, but to embark on a scientific adventure titled “Young Geologist: Secret of The Stones”, a field trip program that introduces children to the secrets of rocks and fossils that hold traces of Earth’s history.

“This activity is part of the Geology Study Program’s initiative at FMIPA UI to foster a love for science from an early age,” said Asri Oktavioni Indraswari, S.T., M.Sc., a lecturer in the Geology Study Program at FMIPA UI. In this event, Asri was assisted by a team of students from her program.

Together with Asri and her team, the children from Hayya Playspace were invited to explore various Earth phenomena through six interactive learning stations.

The secrets explored in this activity were not just about identifying types of rocks or observing fossil shapes, but about how each rock and fossil holds stories of nature’s journey—from the formation of mountains and volcanic activity to the evolution of ancient life.

Di Basic Geology Station, At the **Basic Geology Station**, children were introduced to the Earth’s complex structure, from the crust to the core. They learned that rock faults and folds are not just natural occurrences, but “records” of past geological events.

The adventure continued to the next station, where new wonders of Earth science awaited the curious young explorers. *Mineral Station*, At the *Mineral Station*, the children touched and compared minerals with different lusters and colors, gaining an initial understanding that rocks are not just ordinary lifeless objects but are composed of unique elements with distinct characteristics.

Di *Grain Size Station*, At the **Grain Size Station**, they were invited to become geology detectives by sorting sediments based on their size, understanding how rocks change form during their long journey from mountains to the coast. Here, they learned that the shape and size of rock grains hold clues about their natural journey.

Then, at the next station *Rock Station*, At the **Rock Station**, the children used magnifying glasses to observe rock textures and learned to distinguish between igneous, sedimentary, and metamorphic rocks, uncovering how pressure, temperature, and time shape different types of rocks.

One of the most captivating moments happened at **Fossil Station**. At the **Fossil Station**, the children were invited to leap far back into the past. They saw that fossils are not just imprints of bones or leaves, but traces of ancient life turned to stone—evidence that the Earth was once inhabited by creatures different from those living today.

“By coloring pictures of fossils, the children were encouraged to imagine the colors of life that might have existed millions of years ago,” said Asri.

Finally, in Optical Mineralogy Post, the microscope opens up a new world. Children are fascinated by the crystal structures in rocks that are invisible to the naked eye. This is where they realize that rocks, although they look hard and simple, contain a beautiful and complex little world.

According to Hanny Fauziah from Hayya Playspace, who is also a parent of one of the participants, this activity is very effective in bridging geology with children’s learning methods. “The material is delivered in simple and easy-to-understand language, showing the dedication of the teaching team. Hopefully similar activities will continue,” she said.

This activity is proof that earth science can not only be introduced from an early age, but can also be packaged in a fun and memorable way. Through direct experience, children not only get to know rocks and fossils, but also understand the big story behind it about the ever-changing earth, and the ever-evolving life.