BOOM! Let’s blow open the mountain and drive on through with the 36044 Exploding Tunnel. This large mountain set with realistic stone-finish is a great addition to any BRIO world and conceals a hidden railway passage inside. Insert the TNT into the hole and watch as the mountain explodes to reveal the secret tunnel. Crafted from sturdy plastic and wooden pieces, this train tunnel interlocks easily with other BRIO World toys via the curved wooden track passing through it.