As you step across these beautiful patterns and outlines,consider Portugal’s first “artistic” pavers – prisoners. In 1842,under the orders of Eusebio Furtado,a military engineer and the governor of arms at Castelo de Sao Jorge,the shackled prisoners lay local stones – white (limestone) and black (basalt) stones – in a zigzag design in the castle grounds. This was a departure from the plain,“regular” pavements of the period;cobbled areas of some kind had existed since the 15th century under the orders of King Manuel I. The inventive design was Furtado’s – he likely drew on Roman mosaics and Portugal’s Moorish decorativeazulejos(tiles) – and the ”calcada artistica Portuguesa″ (artistic pavement) was born.

According to historic newspaper articles,the castle’s design innovation created a stir;curious locals made pilgrimages to the castle to see the pattern. Soon after,the municipality employed Furtado to design a paving configuration for the Praca do Rossio. Prisoners undertook this work,starting in August 1848 and completing it in December 1849. The result was incredible – 8712 square metres of a striking wave pattern design,known asmar largo (wide sea) in Portuguese.

Thecalcada artistica Portuguesa spread to other squares,streets and plazas around Lisbon – including Avenida da Liberdade,Largo de Camoes and Praca do Municipio – and other Portuguese towns. In the 20th century,they appeared in Portuguese colonies such as Mozambique,East Timor and Macau,although possibly the most photographed example is in Brazil – the wave motif on the Copacabana Beach promenade,orCalcadao(the word being the superlative of “calcada”).