This is the big flat area in Northern
Italy. It is shaped more or less like a pointy triangle, with the tip aimed at
Genova: the base is the
Adriatic Sea coast, running from
Rimini to
Trieste, the southern side is part of the
Appennini chain (actually this would be the
Appeninno Tosco-Emiliano), and the northern side is parts of the
Alps.
The Pianura Padana forms the flat part of the regions of Piemonte (aka Piedmont), Lombardia (aka Lombardy), Veneto, Friuli Venezia Giulia and Emilia Romagna.
It was formed by the river Po (whose Latin name was Padus, hence the Padana adjective.
The Pianura Padana is the richest part of Italy: it is the productive core of the country for agriculture, food processing, industry, publishing and IT.
Turism focuses on the Adriatic Sea coast and on the historic cities of Venice and Bologna.
for the visitor
This is not the "
mediterranean" Italy you may be thinking of. The climate is continental, people work hard and the picturesque side of things (quaint buildings) is balanced by a remarkable affluence and large
industrial areas.
The pluses for the tourist are the fact that, since this area has a real economy, you get the chance (excluding
Venice, of course) of seeing real people leading real lives.
Furthermore, there are many small towns that hide real jewels of Romanic and Renaissance architecture: you will be able to visit in peace and quiet the cathedrals of Parma, Piacenza, Modena, and the Diamond Palace of Ferrara. Also noteworthy is the Gothic Duomo in Milano. Turin's geometry will surprise you. Trieste is an exquisitely dead city, where the Austro-Hungaric Empire is still alive.
So, when you go to Italy, before heading towards the sweaty hell of Rome ... make a detour: take a secondary train line, go to Sabbioneta or Guastalla, eat the culatello, go to Vicenza (there are only three Renaissance theaters in the world, and one is there), take a look at Alessandria, and discover something.