10 Mythical (and Likely Fictional) Islands That Captured the Imagination

Islands have long symbolized extremes—utopias, purgatories, or idyllic retreats. Mythological islands, in particular, often embody paradise. The Greeks envisioned the Fortunate Islands, or Isles of the Blessed, where the most fortunate souls spent eternity in leisure. Similarly, the Irish spoke of Mag Mell, the Plain of Honey, a divine island paradise reserved for gods and the boldest of mortals.

However, mythology isn’t the sole source of these non-existent islands. Some emerged on maps due to errors by early explorers who mistook icebergs, fog, or mirages for land. Others may have been deliberate fabrications, created to honor the patrons funding the voyages. Even renowned explorer Robert E. Peary is said to have invented “Crocker Land,” a massive Arctic island, to secure backing from financier George Crocker. Despite its non-existence, major institutions like the American Museum of Natural History funded a four-year expedition to locate it.

Like Crocker Land, here are 10 more legendary islands that, though absent from maps, have left their mark on world history, literature, and mythology.

1. Isle of Demons

This mysterious landmass, often shown as two separate islands on 16th- and early 17th-century maps, was said to lie off Newfoundland’s coast. Sailors claimed to hear eerie cries and groans emanating from the fog, giving the island its ominous name.

The island gained a more tangible backstory in 1542 when Jean-François de Roberval, a French nobleman and explorer, was tasked by the king to colonize the North Atlantic coast. He brought his niece, Marguerite de La Roque de Roberval, on the journey. However, after she began a romance with one of Roberval’s officers, he exiled her, her nurse, and possibly the officer to the so-called “Isle of Demons” in the St. Lawrence River. Marguerite gave birth on the island, but her child, lover, and nurse all perished. Despite this, she survived alone for years, defending herself against wild animals with firearms. Rescued by Basque fishermen and later returning to France, she recounted being tormented by “beasts or other shapes abominably and unutterably hideous, the brood of hell, howling in baffled fury,” as documented by explorer Jacques Cartier.

Marguerite’s tale is documented in various historical records, including those by Franciscan friar André Thevet and the queen of Navarre. Yet, the exact location of the “Isle of Demons” remains a mystery. Some experts link it to Quirpon Island in the Strait of Belle Isle, which divides Newfoundland and Labrador. Maritime historian Donald Johnson suggested Fichot Island as the possible site, located along Roberval’s route and inhabited by northern gannets—a species of seabird whose harsh calls during breeding season might have been mistaken for demonic sounds.

2. Antillia

Often referred to as the Isle of Seven Cities, Antillia was a 15th-century cartographic legend believed to exist far west of Spain and Portugal. Its origins trace back to an Iberian tale where seven Visigothic bishops and their followers escaped Muslim invaders in the 8th century, sailing westward to discover an island. There, they established seven settlements and burned their ships to prevent any return to their homeland.

Some versions of the legend claim that visitors to Antillia never leave, while others say sailors can glimpse the island from afar, only for it to vanish as they draw near. Spain and Portugal once disputed ownership of the island, despite its fictional nature, likely due to tales of its shores being rich with precious metals. By the late 15th century, as the North Atlantic was more accurately charted, references to Antillia faded—though its name lives on in the Spanish Antilles.

3. Atlantis

Atlantis, first described by Plato, was said to be a vast island located “beyond the Pillars of Hercules” in the Atlantic Ocean. This once-mighty and peaceful kingdom allegedly sank into the ocean after the gods unleashed a catastrophic earthquake as retribution for its war against Athens. While many have tried to pinpoint its location, Atlantis may simply be a figment of Plato’s imagination. Some archaeologists, however, connect it to the Minoan island of Santorini, north of Crete, which suffered a massive volcanic eruption and earthquake around 1500 BCE, causing its center to collapse.

4. Aeaea

In Greek mythology, Aeaea is the enchanted floating island home of Circe, the goddess of magic. Gifted to her by her father, the sun god, Circe spent her days luring mortal sailors to her island, seducing them, and then transforming them into pigs. Some classical experts believe Aeaea corresponds to the Cape Circeium peninsula on Italy’s western coast, which may have been an island during Homer’s time or appeared as one due to the surrounding marshes.

5. Hy-Brasil

Referred to by various names such as Country o’Breasal, Brazil Rock, Hy na-Beatha (Isle of Life), Tir fo-Thuin (Land Under the Wave), and many others, Brasil (Gaelic for “Isle of the Blessed”) is a legendary island from Irish folklore that surprisingly appeared on numerous historical maps.

Similar to the Mediterranean’s Atlantis, Brasil was described as a paradise of eternal happiness and immortality. It was ruled by Breasal, the high king of the world, who hosted his court on the island every seven years. Breasal possessed the power to raise or submerge the island at will, typically allowing it to be seen only during his grand gatherings.

Legend has it that Brasil was situated 'where the sun meets the horizon, or just beyond it—close enough to glimpse but too distant to reach.' It first emerged on a 1325 map crafted by Genoese mapmaker Daloroto, who portrayed it as a vast region southwest of Ireland. (Subsequent maps relocated it further west.) Typically, it was illustrated as an almost perfect circle, split by a river. Many adventurers sought the island, with some, like Italian sailor John Cabot (Giovanni Caboto), asserting they had discovered it.

Modern experts speculate that Brasil might have referred to Baffin Island, or submerged lands visible only during the last ice age when sea levels were lower, or perhaps an optical illusion caused by layers of hot and cold air bending light.

6. Baralku

In the Yolngu Indigenous culture of modern-day Australia, Baralku (or Bralgu) is known as the island of the deceased. This island plays a pivotal role in Yolngu cosmology—it's believed to be the dwelling place of the creator-spirit Barnumbirr before ascending into the sky as the planet Venus each dawn. Baralku is also the origin point of the Djanggawul, the trio of siblings who shaped Australia's landscape. The island is thought to be located east of Arnhem Land in the Northern Territory, and the Yolngu hold that their spirits journey back there after death.

7. Saint Brendan’s Isle

This landmass was reportedly found by Irish abbot and explorer Saint Brendan of Clonfert and his companions in 512 CE, situated in the North Atlantic, west of northern Africa. Brendan gained fame following the release of Navigatio Sancti Brendani Abbatis (Voyage of Saint Brendan the Abbot), an 8th or 9th-century text detailing his journey to find the wondrous “land of promise” in the Atlantic Ocean. The book became a medieval bestseller, earning the saint the nickname “Brendan the Navigator.” The island was described as densely forested, abundant with lush fruits and flowers. Stories of St. Brendan’s Isle inspired Christopher Columbus and significantly influenced medieval mapmaking, with sightings reported as recently as the 18th century.

8. Ultima Thule

To the Greeks and Romans, Ultima Thule represented the farthest northern edge of their known world. It first appeared in a lost account by the Greek explorer Pytheas, who claimed to have discovered it in the 4th century BCE. The Greek historian Polybius wrote that “Pytheas ... misled many by stating he traversed all of Britain on foot ... and describing Thule, a place where land, sea, and air ceased to exist, replaced by a jelly-like substance where travel was impossible.” Later scholars have identified Thule as the Orkney Islands, Shetland Islands, Iceland, or possibly Norway, while the Nazis believed it to be the ancient origin of the Aryan race.

9. Avalon

First referenced in Geoffrey of Monmouth’s 12th-century Historia regum Britanniae, Avalon is reputed to be the site where the legendary King Arthur’s sword was forged and where he was taken to heal after being injured in battle. The island was believed to be ruled by Arthur’s half-sister, the sorceress Morgan le Fay, along with her eight sisters. By the 12th century, Avalon became associated with Glastonbury in Somerset, linked to Celtic tales of a heavenly “island of glass.” Monks at Glastonbury Abbey during that time claimed to have unearthed Arthur’s remains, though modern historians suspect their find was a ploy to fund repairs for the abbey.

10. Island of Flame

In ancient Egyptian mythology, the Island of Flame, also referred to as the Island of Peace, was believed to be the divine birthplace of the gods and a segment of the kingdom of Osiris. Legend holds that it rose from the primeval waters and was situated far to the east, beyond the realm of the living. This mystical place was eternally illuminated, symbolizing the rising sun.