When the sun sets over Kauai's Kekaha Beach on an especially clear night, a tall, silhouetted tract of land emerges west of the Hawaiian islands, toward the horizon.
For most of the state’s residents, that’s the only way to see the island of Niihau.
It's known as "The Forbidden Island" in Hawaii, and the nickname isn't an exaggeration.
A single family has owned the island for more than 150 years and -- even though it's only 17 miles from resort-lined Kauai -- Niihau remains surprisingly insulated from the outside world.
The island has no roads (dirt trails navigate its arid, bushy terrain), no cars, no stores, and no Internet. Its sandy beaches see more wildlife than human footprints. Sleepy Hawaiian monk seals dot the coast and schools of sharks have been known to swim remarkably close to empty shores.
But the island is populated with people.
When Niihau was purchased by the Sinclair family in the 1860s, the island’s inhabitants -- known as Niihauans -- were allowed to stay, but access to the island by outsiders (including anyone from another Hawaiian island) was restricted.
To this day, only Niihauans, the Robinsons (the descendants of the title-holding family), and the occasional invited guest are allowed there (or near the dozens of homes in the island’s only settlement, Puuwai).
In 1864, King Kamehameha V sold the island of Niihau to the Robinsons' ancestors, the Sinclair family, for $10,000 worth of gold and, according to some accounts, a requirement that the family would promise to preserve the Native Hawaiian language and Niihau’s unique way of life.
'Niihau is yours,” Kamehameha IV said when he signed the contract, according to the New York Times. “But the day may come when Hawaiians are not as strong in Hawaii as they are now. When that day comes, please do what you can to help them.'
(The Niihau Cultural Heritage Foundation reports that Kamehameha IV agreed to sell the land, but died in 1863. Records show that his brother, Kamehameha V, completed the transaction on January 23, 1864.)
Ownership of the island has stayed within the same bloodline ever since and access to the 70-square-mile island has remained extremely restricted.
"We've tried to maintain the request of the King when it was turned over," Bruce Robinson, one of two brothers who owns the island, told ABC News in 2010. "We maintain the island for the people and continue to work it as he had."
Those promises afforded Niihauans a luxury that most modern travelers search the world for: A truly secluded and untouched island.
Niihau remains something of a living fossil -- a glimpse into what life in the islands might look like if, over the centuries, the rest of Hawaii just stood still.
The Niihauans who remain on the island today live mostly as their Native Hawaiian ancestors did, with hunting and fishing taking up the majority of their days. There are an estimated 70 permanent residents on the island, although that number fluctuates as Niihauans move away or return to the islands. The 2010 census listed its population at 170, but since the Robinsons are not required to submit population estimates, the current number of permanent residents are unknown.
They speak mainly Native Hawaiian, but, because of efforts by the island’s only school and Niihauans access to other islands, some residents also know English. They don’t pay rent, they travel mostly by bike or on foot and most homes rely on rain catchments and generators for water and electricity.
They’re also expected to abide by rules set by both the Robinson's and the village’s earlier generations. Alcohol and guns are not allowed on the island and, according to the New York Times, anyone caught breaking the rules can be evicted.
According to one former resident, Niihau men aren’t allowed to have long hair or wear earrings, and on Sundays, the entire village is expected to go to church.