How do lava tubes form?

Lava's surface cools while hot lava flows inside

What shape is a well-known rock inside?

A turtle shaped like Jeju Island

Manjanggul Lava Tube Quiz: Jeju's Giant Volcanic Cave

This Manjanggul lava tube quiz walks underground on South Korea's volcanic Jeju Island. Play 10 interactive questions on how lava tubes form, its length of over 7 kilometers, the section open to visitors, its age, the towering lava column, a turtle-shaped rock, cool year-round temperatures, bats inside, the 1946 discovery and Jeju's UNESCO listing.

Start Manjanggul Lava Tube Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Island
Which island is Manjanggul on?
Type
What is Manjanggul?
Form
How do lava tubes form?
Length
About how long is the Manjanggul lava tube?
Open
How much is open to visitors?
Column
What famous feature ends the walking route?
Turtle
What shape is a well-known rock inside?
Temp
What is the temperature inside like?
Bats
Which animals live in parts of the cave?
UNESCO
When were Jeju's volcanic island and lava tubes listed by UNESCO?

Explanations: answer key for all 10 questions

Q1: Which island is Manjanggul on?
Answer: Jeju
It belongs to South Korea.
Q2: What is Manjanggul?
Answer: A lava tube cave
Lava carved it.
Q3: How do lava tubes form?
Answer: Lava's surface cools while hot lava flows inside
When lava drains, a tunnel remains.
Q4: About how long is the Manjanggul lava tube?
Answer: About 7.4 km
It is one of the world's longer lava tubes.
Q5: How much is open to visitors?
Answer: About 1 km
The rest is protected.
Q6: What famous feature ends the walking route?
Answer: A lava column about 7.6 meters tall
It is among the world's tallest.
Q7: What shape is a well-known rock inside?
Answer: A turtle shaped like Jeju Island
Lava left it on the floor.
Q8: What is the temperature inside like?
Answer: Cool all year
Bring a jacket in summer.
Q9: Which animals live in parts of the cave?
Answer: Bats
Protected sections shelter them.
Q10: When were Jeju's volcanic island and lava tubes listed by UNESCO?
Answer: 2007
Hallasan is included.

Walking Through a Tunnel Carved by Lava

Manjanggul is a lava tube on Jeju Island, South Korea's volcanic island. Lava tubes form when the surface of a lava flow cools and hardens while hot lava keeps flowing underneath. When the lava drains away, a long tunnel remains. Manjanggul formed long ago and stretches about 7.4 kilometers.

Only about 1 kilometer is open to visitors; the rest is protected, partly for bats that live inside. The cave stays cool all year, so visitors bring jackets even in summer. Along the route, lava flowlines mark the walls, and a rock shaped like a turtle, said to resemble Jeju Island, lies on the floor.

The walk ends at a lava column about 7.6 meters tall, among the tallest in the world, formed when lava dripped from the ceiling to the floor. Locals discovered the cave in 1946. In 2007 UNESCO listed Jeju Volcanic Island and Lava Tubes, including Manjanggul and Hallasan.

What This Quiz Teaches

Geology fans will enjoy these questions.

How lava tubes form
How long the cave is
What visitors can see
What lives inside
How it is protected

Did You Know?

The cave floor is uneven, so good shoes help.
Jeju also has a famous tuff cone called Seongsan Ilchulbong.
Dripping water makes some areas damp.
Jeju's haenyeo divers are famous women free-divers.
Black basalt stone walls line Jeju's fields.