Fraser Island
The largest sand island in the world, 1,840 km². Contains dunes that are up to 24 meters high, tall rainforest growing at elevations up to 200 meters, unique ‘vallum’ heaths, and more than 100 unique, crystal clear dune lakes retained in the sand by organic matter deposits.
Sistema Sac Actún
World’s largest known underwater cave system next to Systema Ox Bel Ha, total explored length – 346.7 km.
Víðgelmir
Largest (by volume) lava tube cave in the world. 1,585 meters long cave , with volume 148 000 m³. Contains ice formations, evidence of habitation, possibly from the Viking Age.
Mount Erebus – the southernmost active volcano
One of the few constant glowing lava lakes in the world. Here are found large anorthoclase crystals in the center of the caldera of the volcano.
Dragon Hole
World’s deepest known undersea sinkhole, 300.89 m deep.
Naica Cave of the Crystals
Cave with giant selenite crystals up to 12 meters long and 55 tons heavy. The air temperature in the cave is up to 58 °C high. Now flooded.
Hranice Abyss (Hranicka Propast)
The deepest known underwater cave in the world. The total known depth of this cave is 473.5 m, known depth of the cave lake – 404 m. It is expected that it is much deeper – up to 1200 m deep.
Pozzo del Merro
Extremely deep water-filled sinkhole – a cave with at least 392 m deep waterbody, total measured depth – 472 m.
Iguazu Falls
One of the most enormous and most impressive waterfalls in the world, they are "only" 82 meters tall, but 2,700 meters wide.
Son Doong Cave (Hang Sơn Đoòng)
The biggest known cave in the world. Especially impressive is the more than 4 km long passage that is continuously 90 m wide and up to 200 m high. The total known length of this cave is 9 km. A powerful stream flows through the cave. Here are found unique cave pearls as large as baseballs, as well as green, algae-covered gours.
