We all know about the good ol’ Seven Wonders of the World. Now a Swiss-based organization called New7Wonders has nominated 28 of the most physically sublime and ecologically important locations on our planet to be one of the New Seven Natural Wonders of the World. A global election is being held until November 11, 2011, and of course, among the 28 nominations are ‘Seven Wonders’ shoe-ins like the Grand Canyon or Great Barrier Reef, though virtually unknown underdogs like Poland’s Masurian Lake District or South Korea’s Jeju Island are lobbying for a Cinderella story. But before you click over to the site and cast your bids, here are ten of the lesser-known New Seven Natural Wonders candidates as presented by BootnAll.

Puerto Princesa Underground River, Philippines

The Puerto Princesa Subterranean River in the Philippines flows through a spooky cave of stalactites and stalagmites, bats and spiders, before spilling into the South China Sea. It also supports the Palawan Moist Forest, considered to have the most diverse tree flora in Asia. All 8.2 kilometers of this underworld waterway meander through a complete mountain-to-sea ecosystem and flow by or below eight of the 13 forest types found in tropical Asia. These forests hold over 800 plant species and at least 295 species of trees.

The Sunderbans, Bangladesh and India

The Sundarbans is the largest mangrove forest in the world. This 4,110 square kilometer ‘beautiful jungle’ is traversed by a tightly woven vein system of rivers and tributaries that have created beaches, estuaries, swamps, tidal flats, dunes and levees. 150 species of fishes, 270 birds, 42 mammals, 35 reptiles and eight amphibians call the Sundarbans home, making wildlife the primary draw for visitors.

Mud Volcanoes, Azerbaijan

Mud volcanoes are formed when cold mud, gas and water from kilometers below the earth’s crust are forced upward and expelled into cone shaped mounds on the surface. Of the 700 mud volcanoes identified on land, 400 are located along the Caspian coastline in Azerbaijan, where the typical mud volcano is about four meters in height, though the largest can reach up to 700 meters. And although the tepid globular emission is significantly less molten then their larger erupting volcanic cousins, mud volcanoes can still offer a theatrical performance.

Jeju Island, South Korea

Located off the southern coast of the South Korean peninsula, the volcanic island of Jeju is referred to as Korea’s Hawaii. Though its soft, powdery coastline and sunglasses summer climate aren’t the primary reason Jeju made the cut. Rising 1,950 meters above sea level, Halla Mountain is the highest point in South Korea. In addition to offering four distinct ecological zones, Halla boasts excellent hiking trails to its crater peak, which holds the only natural lake in the entire country. Lava that once flowed from the crater 100,000 to 300,000 years ago formed the Geomunoreum lava tube system. Given their length, frequency, and beautiful crystal formations, these lava tubes are regarded as the best in the world.

Black Forest, Germany

Grandfather evergreens coddle stout Hansel and Gretel cottages. Plump hills adorned with harvest-colored leaves inhale the cold and clean autumn breeze and breathe quiet ripples on a forgotten lake. This is a place of tranquility and intrigue. This is Germany’s Black Forest. The Schwarzwald derived its name from the Romans who called it Silva Nigra, or Black Forest, because of the thick conifer canopy that allowed little light to reach the forest floor. The region encompasses 12,000 square kilometers in southwestern Germany and is one of the country’s top tourist destinations.