Everyone knows Spain offers sun, sea and sand aplenty but fewer know that one of Europe's largest national parks lies in Spain. The country’s interior is a lush, vibrant land which rewards those who swap their flip flops for walking shoes and go exploring.

The 50,720 hectares of Parque Nacional de Doñana are home to several flourishing ecosystems as a result of the warm climate and delta of the Guadalquivir River, the waterway that also flows through the famous cities of Seville and Cordoba.

The park is sandwiched between the towns of Huelva and Cadiz in the southern region of Andalucia. It’s a wetland reserve replete with sand dunes, pine forest and its lifeblood - the marisma (marsh or swamp) which attracts summer wildlife from Africa. Visitors can book guided trips to the protected areas or explore the trails around the El Acebuche visitor centre - the 5km walk leads through scrubland towards the El Acebuche lagoon, home to bird species like purple gallinules - or the 3km nature trail near El Rocio visitor centre. The park is also home to one of the world's largest colonies of Spanish imperial eagles. The beaches along this stretch are stunning – visit Playa de Castilla beach, east of resort town, Matalascañas, but note that there is no access to the national park itself.

Further inland is Granada’s Las Alpujarras region where the deep gorges and valleys towered over by the Sierra Nevada mountains provide picture postcard beauty. The area now forms the Sierra Nevada National Park and is quality walking territory for hikers. You’ll also spot the Spanish ibex, a mountain goat with huge horns. Ham fans might be interested to know that the best cured ham is bred in this high-altitude environment where humidity is low and the air is dry and cool. Trevélez, the highest village in Spain at over 1440m, is renowned for its delicious jamón serrano.

Beach lovers won’t be disappointed here either. Along with spectacular coastal walks, the Cabo de Gata-Nijar Natural Park in Andalucia offers unspoilt shores for everyone from nudists to windsurfers. The water off the peninsula at Cabo de Gata beach is so clear that it’s great for underwater photography as well as usual pursuits like sailing, snorkelling, sea-kayaking and fishing. If you prefer to stay on dry land, explore the mountains and go mountain biking or book 4x4 excursions.

All the way up in northern Spain is Parque Nacional de Ordesa y Monte Perdido in the Aragonese Pyrenees. This is the country’s oldest nature reserve, dating back to 1918. It comprises three separate valleys originating from Monte Perdido ("the lost mountain"), the most famous of which is the Ordesa Valley. The park is a UNESCO World Heritage and a walker’s paradise with high peaks including Monte Perdido itself, looming high at 3,335 m and topped by its glacier. The hub is the village of Bielsa where you’ll find campsites and hotels aplenty.

Another of Spain’s stunning mountain ranges are the Picos de Europa - its western massif towers over the National Park of Montaa de Covadonga, one of Europe’s largest national parks. Due to glacial activity and constant ocean rains, the landscape of the Picos has become ever more dramatic, forming alpine lakes and caverns. Popular with hikers for the quality of trekking, it’s also a hot spot for anglers looking for mountain-fresh salmon and trout.