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The High Wires is an outdoor area of the Secret Mine in the game Luigi's Mansion: Dark Moon. The High Wires is accessed by taking the northwest door inside of the Terminal. The High Wires are two sets of zip-lines that connect the Terminal to the Workshop Landing. The Gondola was presumably connected to this system, but has been out of the use. Between the two zip-lines, there is a small platform with a tree and a nest of crows. The door on the south leads back to the Terminal while the door to the north leads to the Workshop Landing.
During Across the Chasm, Luigi needs to cross the High Wires after melting the ice from the zip-lines via the machine in the Gondola. There is also a treasure chest with coins, bills, and Gold Bars at the end of the second zip-line. During Severe Infestation, the High Wires might be one of the rooms infested with ghosts.
Starting on Hit Rock Bottom and most missions after, Luigi can use the first set of zip-lines to reach the platform with the crows' nest. After defeating the crows, Luigi can use the Poltergust 5000 to vacuum the sapphire inside of the nest.
Only during Across the Chasm, Luigi can melt the ice on the tree using the Gondola's machine. This tree falls over and creates a bridge to an outhouse. Taking the outhouse transports Luigi to a Bonus Challenge where he has to hit three Hiders with snowballs. If Luigi successfully completes the task within the time limit, a treasure chest with a sapphire appears.