10 Under-the-Radar Spanish Islands to Visit Before Everyone Else Does

One of the first things you’ll notice about Lanzarote, the easternmost island in the Canaries,  is the scarcity of man-made eyesores like billboards, malls, and monstrous resorts. Such is the legacy of César Manrique, the Lanzarote-born artist and activist who railed against speculators and developers to preserve—and complement—the island’s geological integrity. The artist’s (woefully underappreciated) masterworks are literally embedded in the island’s landscape: Get a taste of his ingenuity at Tahíche, a Bohemian crash-pad hewn into a volcanic sinkhole, and the Jardín de Cactus, a prickly amphitheater containing 1,100 cactus species. But Lanzarote’s main allure is its stark volcanic beauty, best appreciated at Timanfaya National Park, a 19-square-mile expanse of soaring red peaks and jet-black lava fields—squint and you could be on Mars.

Jutting almost vertically into the air, La Palma, situated northwest of Tenerife, is the world’s steepest island, peaking at an altitude of almost 8,000 feet. Its deep gorges are carpeted with misty pine and laurel forests, setting it apart from the other Canary Islands, which are comparatively parched. Hikers and nature lovers flock here for the challenging ascents, untamed landscapes, and world-class birding; diehard beach bums, on the other hand, should look elsewhere as there’s hardly any sand to speak of. Downtime is best spent in Santa Cruz de la Palma, the island’s colonial capital, where brightly painted 16th-century houses line cobblestone streets and boisterous tapas crawls unfold late into the evening.

Flung three miles off the Galician coast, Ons (population: 78) is the kind of place you might conjure up while eating a sad desk lunch—there are white-sand beaches, scenic hiking trails, old-timey seafood restaurants, and a red-roofed lighthouse that looks like something out of an Edward Hopper painting. Clocking in at three miles long and one mile wide, the island makes a terrific day-trip destination from Vigo, Sanxenxo, Bueu, or Portonovo, the Ons ferry’s ports of call. Once ashore, claim a spot for your towel on the popular Canexol beach, or strike out for the more tranquil Playa de Melide. No trip to Ons is complete without sampling its nationally famous pulpo al estilo de Ons, octopus snipped into tentacled medallions and drizzled with garlic-paprika oil. Find a tip-top version at Casa Checho, a homey restaurant in the postage-stamp village of O Curro.

Quieter and far less developed than its big sibling, Mallorca, Menorca is a slice of paradise (think turquoise waters, abundant wildlife, and seldom-trodden trails) whose unadulterated natural beauty is a rarity in the increasingly over-touristed Mediterranean. Sandy coves, called calas, abound and are ideal for sunbathing to the soundtrack of lapping waves; Cala de Macarella and its tiny offshoot, Macarelleta, are particularly serene. For prime surfing amid craggy cliffs, on the other hand, zip over to Cap de Cavalleria, a beach that sits under the gaze of a towering all-white lighthouse.

In 2000, UNESCO designated the entire island of El Hierro as a biosphere reserve, a testament to its teeming wildlife and singular landscapes ranging from laurel forests to vineyards to jagged cliffs to lava fields. The waters surrounding the island have long been coveted by marine biologists for their abundance of dolphins, whales, and other rare sea creatures, and any diver worth his or her salt knows that El Hierro boasts some of the most stunning underwater seascapes in Europe. (To corroborate this firsthand, sign up for lessons with well-regarded diving academy Centro de Buceo El Hierro.)  Back on terra firma, see if you can spot endemic species like the Atlantic canary or the much, much rarer El Hierro giant lizard on the endless miles of hiking trails veining the island’s interior.

La Gomera might be better-known to linguists than Canary Island holidaymakers, thanks to its ancient, UNESCO-protected “whistled” Spanish called Silbo. Centuries ago, locals developed a whistling register to communicate with one another between La Gomera’s abrupt valleys and steep slopes. Far from endangered today, the “language” is taught in the island’s schools, and though it’s no longer a necessity, Gomeros aren’t shy about showing off their unique skill—particularly after a cerveza or two. Keep your ears pricked while hiking along the sawtooth coast or in the subtropical volcanic interior, with its gravity-defying terraced farms, and you just might hear it.

The only visitable island belonging to the Comunitat Valenciana, Tabarca is a sun-drenched speck in the Mediterranean inhabited year round by just 50 souls. It’s Spain’s smallest inhabitable island. Summer sees the comings and goings of vacationers escaping the crowds of Torrevieja and other nearby resorts, who are eager to swap soaring apartment blocks for charming white lanes and medieval walls. The glass-bottomed catamaran connecting Torrevieja and Tabarca is a wham-bam hit with kids.

This 32-square-mile Balearic island is so hell-bent on preserving its rural, ancestral essence that it has a hotel building freeze with no end in sight: New properties on the island can’t occupy more land (or sky) than the property that preceded it. And unlike Mallorca and Menorca, cruise ships never dock here, making the island a favorite vacation spot among Catalans, Valencians, and even Balearic Island residents. Formentera’s beaches, with Caribbean-blue surf and talc-fine sand, are the island’s biggest selling point: Whether you plant your umbrella at Playa de Llevant, Illetes, or Migjorn, you’re guaranteed idyllic scenery that’ll be the envy of your social media followers.

Were it not for its bracing Atlantic surf and rugged granite outcroppings, you could easily mistake the Islas Cíes for some paradisiacal Bahaman atoll—the sands are that blindingly white. Situated an hour’s ferry ride from the Galician coast, these three islands comprise a nature reserve where squawking seagulls and skittering plovers outnumber their human counterparts. In fact, the tiny archipelago has just three permanent residents and is devoid of hotels, cars, and restaurants. For that reason, most visitors are day-trippers, but there’s always a contingent of solace-seeking campers in the summer months; advance booking is mandatory as there’s a cap on total guests to preserve the environment.

The Galician islet of Arousa might not be as magazine-cover gorgeous as the Islas Cíes or as charmingly lilliputian as Ons, but according to in-the-know Spanish gastronomes, it’s worth visiting for its shellfish alone, plucked straight from the surrounding estuary and served simply boiled with lemon and a few flicks of parsley. Between stops at seafood restaurants to slurp dozens of delectable “Carril” clams from their shells, a local specialty, relax under the sun and watch the tide roll in at any of the island’s seven miles of beaches. At sunset, climb to the O Con do Forno lookout for panoramic views over the scrubby interior and out to the Atlantic.