1 . The Best Caves in The World

Natural caves don’t come much larger than Hang Son Doong, close to the border between Laos and Vietnam. This cave possesses the largest cross-section of any known cave on the planet, a vast area that is difficult to describe. Supposedly, a Boeing 747 could fly through without damaging its wings, but that doesn’t really do justice to the vastness of Hang Son Doong. The stalactites (钟乳石) here are pretty massive too, with some reaching up to 80 metres.

Glowworms (萤火虫) are there, as far as the eye can see. Okay, not literally, but the Waitomo Cave system on New Zealand’s North Island is best-known for the fluorescent fauna that light up the walls, giving it the not-particularly-creative but completely acceptable “Glowworm Caves” nickname. They are more accessible than other caves on this list, with rafting and adventure tours available to those looking for something a little more thrilling.

If you have certain expectations from somewhere called “Mammoth Cave”, that is entirely understandable. Mammoth Cave in Kentucky is the world’s longest known cave system, an incredible 420 miles of underground wonder. That’s twice as long as the next longest, by the way, although it isn’t unusual for the USA to go all out on such things.

Named after the reeds that grow outside, which are used to make flutes, obviously, the Reed Flute Cave’s walls are covered with inscriptions from centuries gone by—if evidence was needed that people have been paying attention to this place for a long old time. The inside part of the cave is also lit up by multicoloured lights, giving it a real otherworldly theme that adds weight to the nickname.

2 . National parks are an excellent way to explore all the beauty that the world has to offer: whether it’s endangered species, erupting volcanoes and snowy mountains, or rainforests and lakes. Of the thousands of national parks that exist in the world, these are the ones that should be on everyone’s bucket list.

Contrary (相反) to the popular link of national parks with the wilderness, it is filled with winding valleys, hills and villages where over 24,000 people live and work. Visitors can walk through grassland, visit waterfalls or explore underground caves, but Yorkshire Dales is also home to several food shops, and the park hosts cheese festivals and farmers markets regularly, so it’s best to go hungry.

It is a delight for those who like a bit of history mixed with the biodiversity of national parks. While it houses thousands of species of wildlife, there’s more to the national park than that.

It is surrounded by striking natural beauty and can be explored by land. But the river national park, as the name suggests, is best explored through leisurely boat rides that take visitors through many ancient towns that come along the way of the river.

Here’s a surprising fact: The whole of Vatnajökull National Park makes up 14% of Iceland’s territory! The park is usually open for hikes around the glaciers; boat rides through glacier lakes, and tours that take visitors through the park’s many ice caves, waterfalls, and icebergs. Vatnajökull is also where two of Iceland’s most active volcanoes are located.

4 . Five Most Beautiful UNESCO World Heritage Sites in the USA

The UNESCO World Heritage Sites are some of the most beautiful places in the world. They represent a unique collection of landmarks, and the five parks in USA really deserve to be treated as such.

 Yellowstone National Park, USA

The world’s first national park sits on top of a volcanic hot spot and offers everything from great views to fun activities and wildlife sightings. Home to lush forests, hot springs, alpine rivers, geyers, and more, it’s not hard to see why it’s one of the greatest parks in the USA.

 Grand Canyon National Park, USA

Thanks to the erosion from the Colorado River, the Grand Canyon is among the best spectacles on the planet. Stretching almost 300 miles, this magnificent valley is almost a mile deep and the width varies between less than a half mile to almost 19 miles.

 Yosemite National Park, USA

Yosemite’s glacial landform secures its spot among the best parks in the USA. This amazing park is also typically recognized because of its huge sequoias (红杉) and granite cliffs. In addition, you’ll find all sorts of picture-worthy meadows, waterfalls, streams, mountains, and a variety of plants and animals.

 Carlsbad Caverns National Park, USA

A karst landscape defines Carlsbad Caverns National Park which houses more than 119 caves. Its two main standouts are the namesake Carlsbad Cavern and Lechuguilla Cave. Both are known for their natural beauty, reef formations, and geologic features, but Carlsbad Cavern is famous for having one of the largest limestone cave chambers in the country at 4,000 feet long while Lechuguilla Cave owes its fame to its rare speleothems, or secondary mineral deposits, that provide a natural laboratory to study biological and geological processes.

 Hawaii Volcanoes National Park, USA

Home to two of the most active volcanoes in the world, Mauna Loa and Kilauea, Hawaii Volcanoes National Park was added to the UNESCO World Heritage List in 1987 in recognition of its outstanding natural values. The park is one of the biggest attractions in Hawaii as it offers visitors dramatic volcanic landscapes and glimpses of rare flora and fauna.