The World Heritage List (UNESCO) -

This is what I have seen so far. The year in parenthesis represents the site's election to the UNESCO World Heritage list.

To view the complete list, click this link

Armenia
 Cathedral and Churches of Echmiatsin and the Archaeological Site of Zvartnots (2000)
 Monastery of Geghard and the Upper Azat Valley (2000)

Australia
 Greater Blue Mountains Area (2000)
 Sydney Opera House (2007)

Austria
 Palace and Gardens of Schönbrunn (1996)
 Historic Centre of Vienna (2001)

Belgium
 Flemish Béguinages (1998)
 La Grand-Place, Brussels (1998)
 Historic Centre of Brugge (2000)
 Major Town Houses of the Architect Victor Horta (Brussels) (2000)
 Plantin-Moretus House-Workshops-Museum Complex (2005)

Canada
 Rideau Canal (2007)

Cyprus
 Paphos (1980)

Egypt
 Ancient Thebes with its Necropolis (1979)
 Historic Cairo (1979)
 Memphis and its Necropolis – the Pyramid Fields from Giza to Dahshur (1979)
 Nubian Monuments from Abu Simbel to Philae (1979)

France
 Palace and Park of Versailles (1979, 2007)
 Paris, Banks of the Seine (1991)
 Historic Site of Lyons (1998)

Germany
 Palaces and Parks of Potsdam and Berlin (1990, 1992, 1999)
 Museumsinsel (Museum Island), Berlin (1999)

Greece
 Acropolis, Athens (1987)
 Archaeological Site of Delphi (1987)
 Medieval City of Rhodes (1988)

Holy See
 Historic Centre of Rome, the Properties of the Holy See in that City Enjoying Extraterritorial Rights and San Paolo Fuori le Mura (1980, 1990) * 11
 Vatican City (1984)

Italy
 Historic Centre of Florence (1982)
 Venice and its Lagoon (1987)
 Historic Centre of San Gimignano (1990)
 Historic Centre of Siena (1995)

Japan
 Historic Monuments of Ancient Kyoto (Kyoto, Uji and Otsu Cities) (1994)
 Hiroshima Peace Memorial (Genbaku Dome) (1996)
 Shrines and Temples of Nikko (1999)

Jordan
 Petra (1985)

Lebanon
 Anjar (1984)
 Baalbek (1984)
 Byblos (1984)
 Tyre (1984)

Luxembourg
 City of Luxembourg: its Old Quarters and Fortifications (1994)

Morocco
 Medina of Fez (1981)
 Medina of Marrakesh (1985)
 Historic City of Meknes (1996)
 Archaeological Site of Volubilis (1997)
 Medina of Essaouira (formerly Mogador) (2001)

Netherlands
 Defence Line of Amsterdam (1996)

Portugal
 Monastery of the Hieronymites and Tower of Belém in Lisbon (1983)
 Historic Centre of Évora (1986)
 Cultural Landscape of Sintra (1995)
 Historic Centre of Oporto (1996)
 Alto Douro Wine Region (2001)

Spain
 Works of Antoni Gaudí (1984, 2005) 23
 Palau de la Música Catalana and Hospital de Sant Pau, Barcelona (1997)

Syrian Arab Republic
 Ancient City of Damascus (1979)
 Ancient City of Aleppo (1986)

Turkey
 Historic Areas of Istanbul (1985)

United Kingdom of Great Britain and Northern Ireland
 Westminster Palace, Westminster Abbey and Saint Margaret's Church (1987)
 Tower of London (1988)
 Old and New Towns of Edinburgh (1995)

United States of America
 Grand Canyon National Park (1979)
 Independence Hall (1979)
 Redwood National and State Parks (1980)
 Statue of Liberty (1984)
 Yosemite National Park (1984)

Yemen
 Old City of Sana'a (1986)
 Historic Town of Zabid (1993)

What I hope to visit before end of my trip in Venezuela:
Venezuela (Bolivarian Republic of)
 Coro and its Port (1993)
 Canaima National Park (1994)
 Ciudad Universitaria de Caracas (2000)