In the late 19th and early 20th centuries, the growth of leisure activities along the coast transformed Oeiras, which became a privileged location for the Portuguese elite. By the beginning of the 20th century, many of the beaches in Oeiras were already occupied by the higher social classes, who travelled to the municipality for medical reasons (believing the air and beach-waters were therapeutic). The construction of National Roadway 6 (EN6) would later link Lisboa to Cascais, permitting new travellers to experience the area, resulting in an influx of new residents that expanded the urban centres, giving rise to beach "chalets" and summer cottages. Simultaneously, the concentration of economic activities in Lisbon and surrounding urban municipalities meant that Oeiras had direct access to the capital.