The little lizards are the island's true celebrities. Once, wall lizards like these ranged across all the Balearic Islands, but the arrival of humans and the predators that came with them wiped them from the large islands and left them clinging to a handful of undisturbed islets. Colom is one of the last strongholds. Its lizards have evolved in isolation into a distinct form, and biologists prize the island as a natural laboratory of how life diverges when a narrow channel of water becomes an unbridgeable border. Sun themselves on the warm rocks and they will approach without much fear; on Colom, they have had few enemies to teach them caution. For a reptile, the island is something close to a lost world, a pocket of the Balearics as they were before people and their animals ever arrived.

For visitors, the draw is the water. Colom's west coast holds two fine-sand beaches, Arenal d'en Moro and Els Tamarells, reached by a short boat hop from the fishing village of Es Grau across a shallow, turquoise channel. The island sits within the S'Albufera des Grau Natural Park, the ecological heart of Menorca and the reason UNESCO named the whole island a Biosphere Reserve in 1993. Protected status keeps Colom undeveloped: no hotels, no roads, no tourist rental of the land, just the beaches, the low scrub, the seabirds overhead, and the lizards underfoot. It is what much of the Mediterranean coast looked like before the resorts arrived.

Colom has not always been so quiet. In earlier centuries the island served as a pesthouse, a place to isolate the sick and quarantine arriving passengers, keeping contagion at arm's length from Menorca's crowded ports. Its separation by water, the very thing that saved the lizards, also made it useful for holding disease at bay. Later it turned to farmland, and a single modest house of about a hundred square meters still stands as the only building on the island. In 1904 the Roca family of Mahón bought Colom, when Antonio Roca Várez took ownership, and it remained in private hands through the generations that followed.

An island for sale is a rare thing, and Colom spent decades on the market. Advertised at roughly six million euros in 2010, it finally sold in 2018 for 3.2 million euros to Alex Meruelo, a Cuban-American businessman born in New York to immigrant parents. Owning it, however, confers less than a buyer might imagine. Because the island lies inside a protected natural park, its proprietor cannot build resorts or rent it to tourists; the same law that guards the lizards also binds the landlord. Colom remains, in every way that matters, a public treasure that happens to be held in a private name.

Approach Colom by boat and it reveals itself slowly: a low green hump ringed by pale sand and clear shallows, the kind of place that looks unchanged for centuries because, largely, it is. Snorkelers drift over seagrass meadows; walkers follow faint paths past the old house to the eastern rocks where the lizards bask in the sun. There are no cafés, no sun loungers, no crowds beyond a summer day's boatload. For an island that has been a plague station, a farm, a family's inheritance, and a billionaire's purchase, Colom wears its history lightly. What it protects best is the small, bright life found here and nowhere else.