Washington/Quebec City  - Mantua and Sabbioneta, two historic cities in northern Italy's Po valley - have been added to the World Heritage list Monday at the UNESCO meeting in Canada.

The sites represent different aspects of Renaissance town planning: Mantua shows the renewal and extension of an existing city, while Sabbioneta 30 kilometres away represents the implementation of period theories about planning an ideal city.

Much of Mantuas layout is irregular with regular parts showing different stages of its growth since the Roman period including many medieval structures among them an
11th century rotunda and a Baroque theatre. Sabbioneta, created in the second half of the 16th century under the rule of Vespasiano Gonzaga Colonna, can be described as a single-period city and has a right angle grid layout.

The two towns offer "exceptional testimonies to the urban, architectural and artistic realizations of the Renaissance, linked through the visions and actions of the ruling Gonzaga family," according to the UNESCO web site. (dpa)