When siblings Yelena and Jorin discover a spiral staircase hidden in their school library, each step transports them to an extraordinary realm. They scale cliffs to visit Bhutan's Tiger's Nest Monastery, snorkel between tectonic plates in Iceland's Þingvellir, and explore Guatemala's mist-shrouded Tikal temples. Along the way they dance with monks, taste local delicacies, catalog rare orchids, and decode ancient glyphs—all while collecting tiny tokens of each land's wonder. Blending humor, heart, and hands-on discovery, Wonders of Hidden Kingdoms invites young readers to explore culture, geography, and ecology through the power of curiosity and the magic hidden inside every book.