Question: When was nanda devi national park added to the unesco list of world heritage?
Disambiguated questions and answers: question: When was the Nanda Devi National Park added to the UNESCO World Heritage Site list?
When was the Nanda Devi National Park expanded to encompass the Valley of Flowers National Park as a UNESCO World Heritage site?
answer: 1988
2005
Natural Questions answer: 1988 (from the Wikipedia article "Nanda Devi National Park")