There are twenty-seven recorded institutional examples of portolan charts and atlases by Placido Caloiro e Oliva.

Oliva’s chart adapts the medieval portolan style to the techniques of early-modern navigation. The main body of the chart is divided into two parts to show both the medieval and corrected views of the Mediterranean, enabling the owner to compare them directly. The corrected axis shows Crete and Cyprus aligned on the same parallel.

Illuminated manuscript double portolan chart, pen and ink and colour wash, heightened in gold and silver, on vellum; coastlines drawn in brown ink extending west to east from the Azores to the Holy Land, and north to south from the British Isles to the north coast of Africa, from western Sahara to the Red Sea; islands in green and yellow; rivers in blue; numerous coastal place-names in red and sepia in semi-italic lettering; thirty city views, including duplicates, with flags; eight full and two half compass roses, all with fleur-de-lys north points; two large elaborate scale cartouches; decorated with sea monsters, sailing ships, galley ships, several land animals (lion, camel, unicorn, deer), palm trees; rhumb lines in green, red, and brown; the whole in a foliate border of red, blue and brown entwined acanthus leaves.

This is a very unusual double portolan chart of the Mediterranean by the celebrated cartographer 

. Linking the medieval and modern, Oliva adapts an honoured but, by then, obsolete tool, the Medieval portolan, to the realities of early-modern navigation. His map shows the features of a traditional portolan, with ample space for medieval bestiary and typified representations of places, but also a chart which records the relative positions of land masses more accurately than the traditionally-calculated angles. 

Oliva, was a leading member of the Oliva family, a cartographic dynasty who dominated portolan chart production in Europe during the sixteenth and early seventeenth centuries. 

s signed by no fewer than sixteen different members of the Oliva family are recorded between 1538 and 1673.

A very unusual double portolan chart of the Mediterranean, linking the medieval and modern, with a committed attempt to adapt an honoured but, by then, obsolete tool, the medieval portolan, to the realities of early-modern navigation. It shows the features of a traditional portolan, with ample space for medieval bestiary and typified representations of places, but also a chart which records the relative positions of land masses more accurately than the traditionally-calculated angles (Wilson). Richly decorated and particularly attractive.

Oliva's 'Doppia' Portolan Chart of the Mediterranean