The Dead Sea, Vietnam's Halong Bay and Australia's Great Barrier Reef are among 28 contenders to be crowned among the world's new seven wonders of nature today.
Swiss foundation New 7 Wonders of Nature organised a world-wide poll in which anyone in the world could vote via telephone, text messages or internet social networks for their favourite sites.
Polls closed at 1111 GMT, with preliminary results to be announced at 1907 GMT.
Among finalists announced in July were Switzerland's Matterhorn peak, New Zealand's Milford Sound and the Galapagos Islands.
Five days before voting ended, the 10 sites leading the polls were the Dead Sea, the US' Grand Canyon, the Great Barrier Reef, Halong Bay, Lebanon's Jeita Grotto, South Korea's Jeju Island, Indonesia's Komodo Island, the Philippines' Puerto Princesa Underground River, Bangladesh's Sundarbans mangrove forest and Italy's Mount Vesuvius.
However, the website shows that voting online accelerated on the last polling day for sites like Germany's Black Forest and the Maldives, while others such as the Iguazu Falls, Jeju Island and the Amazon rainforest fell back.
The poll has attracted great interest, mobilising celebrities including Argentinian football star Lionel Messi calling on fans to pick the Iguazu Falls.
The results come after a long consultation process lasting from December 2007 to July 2009, when world citizens were asked to put forward sites which they deemed were natural wonders.
More than a million votes were cast to trim the list of more than 440 contenders in over 220 countries down to a shortlist of 77.
The group was then further cut to the 28 finalists by a panel of experts.
Founded in 2001 by Bernard Weber in Zurich, the foundation New7Wonders is based on the same principle on which the seven ancient wonders of the world were established by Philon de Byzance in ancient Greece.