Route 520 is the road which connects Kà Âloa and Poipà « to Hawaii Route 50, the principal highway of the southern part of Kauai island in the state of Hawaii. It is under the jurisdiction of Kauai County, though it is numbered within the state numbering system.
Immediately south of where the road meets Route 50, the road (there known as Maluhia Road, meaning "peaceful") enters the Tunnel of Trees, a stand of Eucalyptus robusta, Swamp Mahogany. The stand, which lines either side of the road for more than a mile, providing shade and a characteristic smell. There are two versions of its planting. According to some, the trees were brought here and planted by the Knudsen family, at the time the largest landowner in the area to help stabilize the then soggy road over Knudsen Pass. Another story is that they were planted by pineapple baron Walter Duncan McBryde, who planted them as a community project in 1911, using 500 leftover trees from his landscaping of his estate at Kukuiolono. Before the construction of the Kaumualii Highway (Route 50), the tree tunnel was three times longer than its current size.
As Road 520 enters Kà Âloa, on the west side is the remains of the original Kà Âloa sugar mill, commemorated by a plaque and sculpture, erected in 1985 to commemorate the 150th anniversary of commercial sugar production in Hawaii. The road forms a T with Kà Âloa Road at the center of Kà Âloa, and then continues to the south a few blocks further west under the name "Poipà « Road." Kà Âloa Road continues west as Hawaii Route 530 continuing on south to Poipà «. Poipà « Road then splits off to the east to most of the town of Poipà «. Route 520 then continues as LÃÂwai Road briefly, before it splits to the west leads to Spouting Horn and the National Tropical Botanical Gardens. The final stretch of the highway is marked as Hoonani Road, and terminates at Kà Âloa Landing.
The Maluhia Road section was formerly designated as Hawaii Route 52.