Cantabrian Coast, the green strip between the mountains and the sea.

What is the Cornisa Cantábrica?

The name given to the narrow strip of northern Spain between the Cantabrian mountains and the Cantabrian Sea. It is not an administrative region: it usually includes the coast of Lugo, Asturias, Cantabria and the Basque Country, from the Mariña lucense to the mouth of the Bidasoa, on the French border. In some places all of Galicia is counted; here we mean the coast that faces north.

What defines it is the closeness of mountain and sea. In a few kilometres you go from a beach to a mountain pass, and from many stretches of coast you can see the Picos de Europa. The climate is oceanic: mild summers, rain spread across the whole year and a green that lasts even in August. The tides are large, and the same beach changes completely between low and high tide.

How to get around by car, train or on foot?

By car is the most convenient. The A-8 motorway, the Cantabrian one, follows almost the whole coast: from Bilbao to Santander it is about a hundred kilometres, an hour's drive, and from Santander to Oviedo about two hundred, around two hours. In the Basque Country, the AP-8 is a toll road. The towns and beaches are always a few minutes from the motorway along minor roads, which is where you see the coast.

Renfe's metre-gauge train, the former FEVE, links Bilbao, Santander, Oviedo and Ferrol along the coast. It is slow: from Santander to Oviedo, about five and a half hours, with few trains a day, and from Bilbao to Santander, about three hours. It is good for short stretches and for reaching towns like Llanes or Ribadesella without a car, not for covering the cornisa end to end in a few days. Long-distance buses between capitals are faster.

There are airports at Bilbao, Santander and Asturias, with flights from Madrid, Barcelona and other cities, and at A Coruña for the Galician end. A good option is to fly into one airport, hire a car and return it at another, although that usually carries a surcharge.

On foot, the Camino del Norte of the Camino de Santiago follows this coast from Irún. Many towns also have signposted coastal paths of a few hours, such as the one at Llanes, which let you walk the cliffs without doing the whole Camino.

What to see from east to west?

In the Basque Country, the Gipuzkoa coast begins at Hondarribia, with its walled old town, and continues through San Sebastián to Getaria and Zarautz. In Bizkaia, the Urdaibai Biosphere Reserve brings together Gernika, the Mundaka ría and San Juan de Gaztelugatxe; Bilbao is half an hour away.

In Cantabria, the eastern coast has Santoña and Laredo, with anchovy factories you can visit. West of Santander, the Costa Quebrada and Liencres is a stretch of cliffs and dunes; Santillana del Mar combines the medieval town and the Altamira Neocave; Comillas has Gaudí's Capricho; and San Vicente de la Barquera is the fishing town on the ría, with Oyambre next door. Inland, Liébana and Potes lead to the Picos de Europa, and Alto Campoo is the Cantabrian ski resort.

In Asturias, the eastern coast has its base at Llanes, with dozens of beaches and the coastal path, and at Ribadesella the Tito Bustillo cave and the mouth of the Sella. Further west, past Gijón and Avilés, Cudillero hangs its houses above the port, and Luarca follows the same idea.

In the Mariña lucense, already in Galicia, As Catedrais beach, in Ribadeo, is the usual end of the trip: rock arches that can only be walked at low tide.

Rock art is a thread that ties the whole cornisa together. The Altamira cave and seventeen more caves in Cantabria, Asturias and the Basque Country form a single World Heritage Site; several are visited with small quotas, and it is wise to book ahead.

When to go and what changes each season?

June and September are the best months: long days, temperatures of twenty to twenty-five degrees and fewer people. July works well, and August is the busiest month, with expensive accommodation, packed towns and difficult parking at the well-known beaches. In spring and autumn it rains more, but the coast can be seen without crowds and the villages stay open. From November to February storms are frequent; the seafronts and the cliffs in a heavy sea are a spectacle, but many activities close.

The Cantabrian water is cool even in August, and you should allow for some rainy days at any time. Always carry a rain jacket and a warm layer for the evening.

How many days and how to divide them?

In a week you can do one stretch well, for example Cantabria and eastern Asturias, with two bases. For the whole cornisa from Hondarribia to Ribadeo you need ten days or two weeks, with three or four bases: one in Gipuzkoa or Bizkaia, one in Cantabria, one in eastern Asturias and another in the west. With a weekend, choose a single area: Santander with Santillana and Comillas, or Llanes with Ribadesella.

What to know before you go?

Check the tides before going to a beach: some almost disappear at high tide, and certain coves can only be reached at low tide. As Catedrais beach requires a free authorisation from the Xunta at Easter and in summer, from July to September; it is requested on its website. The caves with rock art have limited places and sell tickets in advance. In summer, book accommodation weeks ahead, especially in August and at weekends.