Cabaña Verónica, Spain For me, a proper mountain shelter should be compact, reached only after a demanding walk, and preferably come with an unusual story. Cabaña Verónica, high in the Picos de Europa, meets every requirement. Sleeping six people at 2,325 metres, it takes around two hours to reach from the nearest cable-car station, let alone from any road. The panorama is extraordinary, and the welcoming warden keeps the refuge in excellent shape. Its greatest appeal, though, is its past life:

In 1970, the release of the most successful nature record ever made brought whale song to a huge audience and permanently changed the way people thought about whales. It was 1952, at the peak of the Cold War. US sonar engineer Frank Watlington was working off Bermuda, listening beneath the waves for Soviet submarines and signs of seismic activity. Watlington used an early hydrophone system: long cables fitted with microphones that could be lowered deep into the sea. Whatever military signals he