The first park of its kind in Greece and the largest protected marine area in Europe, the National Marine Park of Alonissos covers seven Greek islands, is home to numerous marine animals, and has several archaeological landmarks. Swimming, diving, and snorkeling are some of the best ways to get acquainted with the park, although boat rides, beach days, and island visits are other options. However you explore this sunny marine park, look out for the rare Mediterranean monk seal.

The UNESCO-listed Plitvice Lakes National Park was the first designated national park in Croatia, and remains to this day one of the country’s most popular destinations. Comprised of 16 interconnected lakes—ranging from shocking blue to sultry greens and grays depending on the time of day—Plitvice Lakes National Park is crisscrossed by sinuous wooden boardwalks that weave across the water, way-marked hiking trails, and cascading falls that will make you glad you left the house.

More often than not, Italy conjures up images of heaping plates of pasta, picturesque shorelines, and islands set against glistening ocean-blue backdrops. However, the country is also home to a spectacular forested national park, just a few hours outside Florence. Spanning both Tuscany and Emilia-Romagna, the Casentinesi Forest National Park is home to a variety of Italian flora and fauna, tumbling waterfalls, and mountain peaks. You can even admire Etruscan ruins and an ancient monastery.

Spain’s answer to the Lake District, Aigüestortes i Estany de Sant Maurici National Park in the Pyrenees is Catalonia’s only national park. Marked by pine forests, shimmering lakes, peat bogs, and rugged peaks, the park is popular among hikers, climbers, and bikers alike. But the real magic of Aigüestortes i Estany de Sant Maurici National Park lies in its seasonality—in winter, the park is an ideal spot for skiing, snowshoeing, and sledding.

Tucked into the northern reaches of Portugal, right on the border with Spain, the Peneda-Gerês National Park is the only official national park in the country. Characterized by rocky outcrops, including the eponymous Serra da Peneda and the Serra do Gerês, this national park is a hiking and kayaking hub. Look out for remote villages and Roman bridges, dense forests populated by wolves and wild boar, as well as a rare flower found in the park—the Serra do Gerês iris.

Occupying a vast swath of north Wales, the Snowdonia (Eryri) National Park encompasses a beachy coastline, the country’s tallest peak, and Wales’ largest natural lake. Come for the myriad hiking trails, mountain biking center, and adventure activities, from below-ground trampolines to ziplines and toboggans. Then, stay for the culture of Welsh-speaking villages such as Beddgelert and Betws-y-Coed, fresh mountain air, and a triptych of nearby castles—Caernarfon, Conwy, and Harlech.

Rolling heather-clad moorland, quintessential English vistas, starry skies, and a network of limestone caves comprise the Yorkshire Dales National Park in northern England, also home to Bolton Abbey and Wensleydale Creamery. From the lush low-lying dales to the craggy, windswept peaks of Ingleborough and Pen-y-ghent—part of the Yorkshire Three Peaks Challenge—the Yorkshire Dales National Park is one of the best places to enjoy the great European outdoors, whether on foot, by bike, or train.

A major bird-watching region and stretch of protected wetlands in south-western Estonia, Soomaa National Park is made up of peat bogs, grassland, dunes, forests, and rivers. Visit in one of Soomaa’s five distinct seasons—the classic four plus high-water season—to enjoy this overlooked national park on foot year-round, or by traditional dugout canoe from April to October. In winter, strap on your snowshoes or skis to explore the frozen bogs.

Spectacular glaciers—including the largest in Europe—icy lagoons, and active volcanoes combine to make Vatnajökull National Park. Divided into four cardinal quadrants, head north for crashing glacial rivers, east for snowy peaks, and west for black-sand beaches with subglacial volcanoes, including Grímsvötn. It’s the southern stretches of the park that are most popular though, home to Iceland’s tallest mountain, Hvannadalshnjúkur, and the Skálafellsjökull glacier.