This small town in the north of the island is one of the key spots where tourism in Tenerife first really took off. It can actually be traced to a onetime sanatorium dedicated to treating foreign patients, especially from elsewhere in Europe. Today it's a mecca for the healthy from all over the continent and beyond, drawn to its lovely port and a collection of historic sites and architecture truly astonishing for such a relatively small place. Two in particular not to miss are the Casa Amarilla (Yellow House) and the Casa de la Aduana (Customs House), which has stood since 1610. The San Telmo promenade is another wonderful spot, as is, of course, Playa Jardín, one of Tenerife's most popular black-sand beaches.