Question: The daily newspaper, laRegioneTicino is based in a city famous for its three castles that have been UNESCO World Heritage Sites since what year?

Context paragraphs:
List of World Heritage Sites in South Africa: The United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention, established in 1972.  South Africa accepted the convention on 10 July 1997, making its historical sites eligible for inclusion on the list.  As of 2016, there are eight World Heritage Sites in South Africa, including four cultural sites, three natural sites and one mixed site.

List of World Heritage Sites in Turkey: The United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention, established in 1972.  Turkey accepted the convention on 16 March 1983, making its historical sites eligible for inclusion on the list.  As of 2017, there are seventeen World Heritage Sites in Turkey, including fifteen cultural sites and two mixed sites.

List of World Heritage Sites in Thailand: The UNESCO (United Nations Educational, Scientific and Cultural Organization) has designated five World Heritage Sites in the Thailand.  The UNESCO World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention.

List of World Heritage Sites in Colombia: The United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention, established in 1972.  Colombia accepted the convention on 24 May 1983, making its historical sites eligible for inclusion on the list.  As of 2016, there are eight World Heritage Sites in Colombia, including six cultural sites and two natural sites.

Bellinzona: Bellinzona (] ; French: "Bellinzone" ] , German: "Bellenz" ] , Romansh: "Blizuna" ] ) is the capital of the canton Ticino in Switzerland.  The city is famous for its three castles (Castelgrande, Montebello, Sasso Corbaro) that have been UNESCO World Heritage Sites since 2000.

List of World Heritage Sites in the Philippines: The UNESCO (United Nations Educational, Scientific and Cultural Organization) has designated six World Heritage Sites in the Philippines.  The UNESCO World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention.

List of World Heritage Sites in Malaysia: The UNESCO (United Nations Educational, Scientific and Cultural Organization) has designated four World Heritage Sites in Malaysia.  The UNESCO World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention.

List of World Heritage Sites in Tanzania: The UNESCO (United Nations Educational, Scientific and Cultural Organization) World Heritage Sites are places of importance to cultural or natural heritage as described in the UNESCO World Heritage Convention, established in 1972.  Tanzania ratified the convention on 2 August 1977, making its historical sites eligible for inclusion on the list.  Tanzania has 7 UNESCO world heritage sites and two of them are placed on the world heritage sites in danger.

LaRegione Ticino: The laRegioneTicino (English: "The Ticino Region") is a Swiss Italian-language daily newspaper, based in Bellinzona, Ticino with regional divisions in Locarno, Lugano and Chiasso.  It was founded in 1992 from the merger of "Il Dovere" and "L'Eco di Locarno".  The newspaper's editor-in-chief is Giacomo Salvioni.

Castles of Bellinzona: The Castles of Bellinzona are a group of fortifications located around the town of Bellinzona, the capital of the Swiss canton of Ticino.  Situated on the Alpine foothills, the group is composed of fortified walls and three castles named Castelgrande, Montebello and Sasso Corbaro.  Castelgrande is located on a rocky peak overlooking the valley, with a series of walls that protect the old city and connect to Montebello.  Sasso Corbaro, the highest of the three castles, is located on an isolated rocky promontory south-east of the other two.  The Castles of Bellinzona with their defensive walls have been an UNESCO World Heritage Site since 2000.

Supporting paragraphs: LaRegione Ticino Bellinzona
Answer: 2000