Five of the world's natural wonders have been nominated for inclusion on the UN World Heritage List.
A biodiversity-rich rainforest in Madagascar and Tenerife's volcanic landscape are among the sites favoured by the World Conservation Union (IUCN).
A total of 37 natural and cultural sites will be considered by the UN World Heritage Committee.
The committee will make its final decision at its annual meeting, which begins on 23 June in New Zealand.
The prestigious list, co-ordinated by the UN Educational, Scientific and Cultural Organization (Unesco), was set up to ensure the long-term protection of globally important cultural and natural sites.
The five locations selected for consideration by the IUCN, an official advisory body to Unesco, are:
- South China Karst: described as being unrivalled for the diversity of its karst features - a unique underground landscape formed by water eroding limestone and marble rocks
- Rainforests of Atsinanana, Madagascar: home to a unique array of species, 80-90% of which are only found on the island nation. Deforestation has destroyed more than 90% of the original forest
- Jeju volcanic island, Korea: includes a shield volcano that is about 1.2 million years old, and an "impressive and significant" system of lava tubes (underground tunnels formed by lava flows)
- Primeval beech forests, eastern Europe: found in Slovakia and Ukraine, the woodlands are "an outstanding example of undisturbed, complex temperate forests"
- Teide National Park, Spain: situated on the island of Tenerife, the park was nominated for its "mature, slow-moving and geologically complex volcanic system"
The IUCN will also propose that the committee considers taking action to improve the level of protection for existing World Heritage sites that have been identified as being at risk.
These include the Galapagos Islands, where the number of tourists have increased to more than 120,000 per year - a three-fold increase over the past 16 years.
The islands were made a World Heritage Site 30 years ago for their unique plant and animal life.
The diversity of species found on the Pacific archipelago inspired naturalist Charles Darwin and helped him develop his theory of evolution.
Down not out
Charles Darwin's home and workplace in southern England, Down House, has been formally removed from this year's nomination list by the UK government.
Culture Minister David Lammy made the decision after receiving advice from the International Council on Monuments and Sites (Icomos).
The assessment raised questions about the "outstanding universal value" of the bid.
However, the government said it felt the council failed to recognise the site's significance to the heritage of science and confirmed that a renewed submission would be presented in 2009.