Unesco has announced the annual update to its prestigious World Heritage list, adding 21 new locations deemed of cultural and historical importance to its global list of more than 1,000.

India leads the way this year with three new allocations, while Iran and China also gained multiple inclusions, with two new World Heritage sites a piece.

Located at the heart of the Himalayan range in Sikkim, the Khangchendzonga National Park is India’s newest addition, with the site offering a unique diversity of plains, valleys, lakes, glaciers and mountains, including the world’s third highest peak, Mount Khangchendzonga. Additionally, the Archaeological Site of Nalanda Mahavihara in Bihar comprises the archaeological remains of a monastic and scholastic institution dating from the 3rd century BC to the 13th century AD. India is also part of The Architectural Work of Le Corbusier, which crosses multiple countries and continents.

In Iran, the Persian Qanat – an underground system used to transport and create a reliable supply of water for human settlements in hot climates – provides “exceptional testimony to cultural traditions and civilisations in desert areas with an arid climate,” according to Unesco. Dating back as far as 700 BC, Iran’s qanats are still in use today. Additionally, the World Heritage Committee has also added the Lut Desert to its list, with the area presenting some of the “most spectacular examples of aeolian yardang landforms” – a series of giant corrugated ridges.

China’s Zuojiang Huashan Rock Art Cultural Landscape – located on steep cliffs in the border regions of the southwest of the country – is one of the most eye-catching additions to the list. In a surrounding landscape of karst, rivers and plateaux, 38 sites of rock art dating back to 5th century BC illustrate the life and rituals of the Luoyue people.The country also hosts a second new addition to the World Heritage list, with Hubei Shennongjia – an area of rich biological diversity – also recognised by Unesco.

The Architectural Work of Le Corbusier, an Outstanding Contribution to the Modern Movement is perhaps the most unique of the additions, as it comprises 17 sites across seven countries – Argentina, Belgium, France, Germany, India, Japan and Switzerland.

Le Corbusier – who was a pioneer for the modern movement following World War One – was well known for using iron, concrete and glass to create bold lines and functionality not seen at the time.

Inscribing the 17 sites to the World Heritage list, Unesco said the works reflected "a new architectural language that made a break with the past", adding that sites such as the National Museum of Western Art in Tokyo and the House of Dr Curutchet in La Plata, Argentina, reflected how the Modern Movement sought to meet "the challenges of inventing new architectural techniques to respond to the needs of society".

The UK also gains a site, with Gorham's Cave Complex – located within the steep limestone cliffs on the eastern side of the Rock of Gibraltar – offering archaeological and paleontological deposits that provide evidence of Neanderthal occupation over a span of more than 125,000 years. This is Gibraltar’s first site to become a World Heritage site, and with it the UK’s 30th.

Full list of new UNESCO World Heritage Sites

• Stecci – Medieval Tombstones Graveyards (Bosnia and Herzegovina, Croatia, Montenegro, Serbia)

• Archaeological Site of Philippi (Greece) • Antequera Dolmens Site (Spain)

• Archaeological Site of Ani (Turkey) • Gorham's Cave Complex (United Kingdom)

• The Architectural Work of Le Corbusier, an Outstanding Contribution to the Modern Movement (Argentina, Belgium, France, Germany, India, Japan, Switzerland)• Antigua Naval Dockyard and Related Archaeological Sites (Antigua and Barbuda)

• Pampulha Modern Ensemble (Brazil)• Khangchendzonga National Park (India)

• Hubei Shennongjia (China)• Mistaken Point (Canada)

• Archipielgo de Revillagigedo (Mexico) • Sanganeb Marine National Park and Dungonab Bay - Mukkawar Island Marine National Park (Sudan)

• Lut Desert (Islamic Republic of Iran) • Western Tien-Shan (Kazakhstan, Kyrgyzstan, Uzbekistan)

• Ennedi Massif: Natural and Cultural Landscape (Chad)• The Ahwar of Southern Iraq: Refuge of Biodiversity and the Relict Landscape of the Mesopotamian Cities (The Republic of Iraq)

Zuojiang Huashan Rock Art Cultural Landscape (China) • Archaeological Site of Nalanda Mahavihara (Nalanda University) at Nalanda, Bihar (India)

• The Persian Qanat (Islamic Republic of Iran)• Nan Madol: Ceremonial Centre of Eastern Micronesia (Federated States of Micronesia)