A square in a circle: this is the symbol which identifies all the goods of the world natural and cultural heritage, whose preservation and conservation is a fundamental duty of the international community, in order to give to the future generations the opportunity to appreciate their beauty.
This concept has been qualified from a juridical point of view in an important document at universal level, the Convention for the protection of the world heritage, in force since 1972 in the UNESCO: its main objective is to guarantee the full respect and defence of natural and artistic treasures by both individual and collective action of countries in which these goods are.
Since 1972, 153 countries have been requested to assure the protection of 552 very interesting sites and places, like temples and historic centres of cities, natural areas and archaeological sites, single monuments or monumental complexes, castles and caves, mountains, fenlands and islands.
There are exact procedures of action to identify, study and preserve concretely these goods.
The Committee for the World Heritage is competent for the adoption of fundamental decisions in the process of choice of goods and sites to be listed in the List of the World Heritage, in cooperation with three not governmental organizations, ICOMOS (International Council for Monuments and Sites), IUCN (World Union for Conservation), and ICCROM (International Center for the Study of Preservation and Restoration of Cultural Goods). The Committee is requested to protect concretely the goods in the List, even by the specific Fund for the World Heritage (supported by the compulsory contributions from UNESCO member States - not higher than 1% of the contribution fixed for financing UNESCO activities - and by the voluntary contributions from countries, organizations and privates), giving a technical and financial support, if it's necessary to guarantee the action of protection of these goods.
With the Committee, since 1992, there is another body, the UNESCO Center for the World Heritage: it's competent for the organization of conferences and debates in calendar, for the assistance to member states in order to identify the sites to be listed and to draft reports about the state of conservation of goods already listed (which shall be examined and approved by the Committee), to act for the protection of one particular good in case it will be in danger, to give wide information about UNESCO initiatives (in particular those of the Committee for the World Heritage), for a real protection of the goods.
Which are the fundamental criteria for the natural and cultural goods to be included in the List of the World Heritage? There are specific criteria for the selection: an artistic monument, for example, could represent a specific culture and could have influenced the artistic production, in a certain historic period, by the creation of a special achitectonic style, while a natural site could be very beautiful, or be very interesting from an ecological or biological point of view. Then, if this good is very endagered, it is listed in the List of the World Heritage in Danger, a second list more limited if compared with the general List.
In Italy there are 27 places which are listed in the List of the World Heritage at the UNESCO (28, if you consider the Holy See, too):
1979 Rock Drawings in Valcamonica
1980 Church and Dominican Convent of Santa Maria delle Grazie with "The Last Supper" by Leonardo da Vinci
1982 Historic Centre of Florence
1987 Venice and its Lagoon
1987 Piazza del Duomo, Pisa
1990 Historic Centre of San Gimignano
1993 I Sassi di Matera
1994 The City of Vicenza and the Palladian Villas of the Veneto
1995 Historic Centre of Siena
1995 Historic Centre of Naples
1995 Crespi d'Adda
1995 Ferrara, City of the Renaissance
1996 Castel del Monte
1996 The Trulli of Alberobello
1996 The Early Christian Monuments and Mosaics of Ravenna
1996 The Historic Centre of the City of Pienza
1997 The 18th-Century Royal Palace at Caserta with the Park, the Aqueduct of Vanvitelli, and the San Leucio Complex
1997 The Residences of the Royal House of Savoy
1997 The Botanical Garden (Orto Botanico), Padua
1997 The Cathedral, Torre Civica and Piazza Grande, Modena
1997 The Archaeological Areas of Pompei, Ercolano, and Torre Annunziata
1997 Villa Romana del Casale
1997 Su Nuraxi di Barumini
1997 Portovenere, Cinque Terre, and the Islands (Palmaria, Tino and Tinetto)
1997 The Costiera Amalfitana
1997 The Archaeological Area of Agrigento