If you have cravings for adventure, feelings of wanderlust, and are not claustrophobic, these five travel destinations listed by CNN contributor Carren Jao must be perfect for you.
Mexico: La Cueva de los Cristales
Don't expect to see delicate clusters of crystals in this cave, which is found in the Naica Mine near Chihuahua. In the Cave of the Crystals, you'll find huge gypsum columns crisscrossing throughout the cave, hence its name. And this is the only place, so far, where you'll find this kind of astounding sight. In fact, its massive crystals are some of the largest in the world today. What's also amazing is that this awesome attraction was discovered only in 2000. Visits are said to be "nearly impossible" because of its dangerous conditions. Temperatures can run up to 136 degrees and humidity is at a high 100 percent. There's also a pool of magma warming things up below the cave. Make a point to go this place when conditions finally allow visits.
Philippines: Puerto Princesa Underground River
Coolness credentials: world's second longest underground river at 5.1 miles, UNESCO World Heritage site, one of the New Seven Wonders of Nature, and contains massive chambers (the largest is at 390 feet wide and nearly 200 feet high). Plus, the surrounding park is home to at least 800 plant species and a diverse fauna.
Iceland: Thrihnukagigur Volcano's Magma Chamber
In these modern times, you don't need to be a sacrificial victim just to see what's inside Thrihnukagigur Volcano, which remained dormant for 4,000 years. There's still no clear explanation how the magma "mysteriously drained away." What's left behind in its place are "psychedelic mineral colorations geological geeks can gawk at." Take a tour inside the volcano's bowels between June and July.
New Zealand: Waitomo Glowworm Caves
This is the next best place for that out-of-this world experience similar to that of being in the middle of space, surrounded with nothing but many glittering stars against a dark backdrop that is the universe. These caves, which are two hours south of Auckland, are decked out with arachnocampa luminosa, glowworms native to New Zealand.
Brazil: Poço Encantado
The "Enchanted Well" looks enchanting indeed - an underground lake with a small hole for a window where sunlight streaks through, hits the water, and turns the impossibly clear waters into deep blue. You can see as far as 200 feet to the bottom, where there are rock formations and "ancient tree trunks." And zero monsters.