This Article Contains information directly from the Pikmin Games. This article is based off of an Enemy/Treasure/Area/Cave/Pikmin/Character from the Pikmin series of Games.
The Unspeakable Wonder is a golden crown which closely resembles that of Princess Peach from the Super Mario series. It is found on top of a snowman in the Valley of Repose, near the Frontier Cavern. After clearing a path, be wary of the Armored Cannon Beetle Larva buried near the treasure. This beast has the vantage of location, so it can be difficult to attack. Try to have it release a rock down one side of the slope, then run up the other side quickly with Pikmin and throw them onto its body; when they are flung off, whistle them back up. This strategy should mean that the Cannon Beetle does not turn around, as long as Pikmin are quickly thrown back on.
Because of its position, the treasure itself can be difficult to get Pikmin to carry. They often cannot reach the ground while holding it, and takes a long time to maneuver into a suitable position. The best approach is to throw Pikmin at all sides of the crown, and to avoid using Purple Pikmin.