What kid (‘big’ or small) doesn’t like playing in the dirt and treasure hunting? Put those two wholesome activities together, add some fresh air and sunshine, and there’s the perfect weekend adventure awaiting your family at Thunderbird Park in the Gold Coast hinterland. “Thundereggs” are what you will be hunting at Thunderbird Park on Tamborine Mountain. Thundereggs are generally solid crystals in formation, ranging in size from golf balls to tennis balls and larger, and are found in flows of prehistoric rhyolite lava. They formed 200 million years ago in gas pockets in the lava. This site features the world’s largest thunderegg crystal mine. This is one unique day trip that you have to experience at least once in your lifetime – but we know you’ll become addicted!