day · fixed · day 157 of 365

National Caves and Karst Day

Explore a local cave or karst and enjoy the sometimes alien beauty and wildlife that lurks in these stunning and underappreciated features of nature.

Hobbies & Activities Nature & Environment42

Marketing angleinferred

Drive family cave tourism and educational experiences by positioning National Caves and Karst Day as a gateway to unique underground adventures and nature appreciation.

Relevance 42medium intent

Plan your family cave adventure: 5 must-see show caves near you
Underground wonders: What wildlife and geological features await in karst systems
Beyond the typical vacation: Why cave exploration is the ultimate nature-learning experience
Celebrate our planet: How cave tourism supports conservation efforts

History

National Caves and Karst Day first started in 2017 and has played a huge part in promoting the exploration of caves in the United States, Bermuda and Barbados since then. In particular, there are 90 show caves that are focused on because these are safe, accessible and overseen by the National Caves Association.

Each year, people turn out on National Caves and Karst Day and take the time to appreciate some of the most incredible natural sites that you’ll find in this part of the world.

They might be hidden away but people quickly realize what they’ve been missing when they explore these caves for themselves.

How to celebrate

Head Out to the Caves

Spending time in the caves is great for families because children love this kind of exploration and gives them time to learn a lot. The caves offer many fun experiences and that’s something not everyone realizes. Cave tours can see underground rivers and even take kayak and boat tours on them. It’s the kind of experience that you and your family have probably never had before.

Observe Wildlife

Depending on the time of year, there are also various kinds of wildlife that can be seen there, and that’s fantastic for families to experience together. When National Caves and Karst Day arrives, you should celebrate it by exploring an NCA cave near you.

Appreciate Nature

As you can see, there are lots of reasons to celebrate National Caves and Karst Day and lots of fun to be had with your family in doing so. Our planet is precious and the more we understand and appreciate it, the better it is for us and it going forward, so why not make the most of National Caves and Karst Day?

FAQ

What is a karst landscape and how does it form?

A karst landscape develops where slightly acidic water dissolves soluble rocks, most often limestone, dolomite, or gypsum. Over thousands to millions of years, rainwater and soil water absorb carbon dioxide to form a weak carbonic acid that seeps into fractures in the rock. This process enlarges cracks into conduits, caves, sinkholes, and underground drainage networks, creating distinctive features such as disappearing streams, springs, and rugged limestone hills.

Why are karst aquifers so important for drinking water?

Karst aquifers supply drinking water to hundreds of millions of people worldwide because they can store and transmit large volumes of groundwater through their extensive network of fractures, conduits, and caves. In some regions, especially where surface water is scarce or seasonal, karst aquifers provide the primary or only reliable source of fresh water. Their high permeability allows rapid recharge, but it also means they are more vulnerable to contamination than many other aquifer types.

What makes cave ecosystems different from surface ecosystems?

Cave ecosystems are shaped by permanent darkness, relatively stable temperatures, and limited nutrients. Many cave animals have evolved specialized traits such as loss of pigment and eyes, elongated limbs or antennae, and slow metabolism to cope with scarce food and the absence of light. Energy typically enters caves from the surface through organic debris, groundwater, or bat and bird guano, so cave communities are closely tied to the health of the surrounding landscape above ground.

How do caves help scientists study Earth’s past climate?

Mineral deposits in caves, known as speleothems, grow in thin layers as water drips and leaves behind dissolved minerals such as calcite. The chemistry and isotopic composition of these layers record information about past rainfall, temperature, and vegetation. By dating and analyzing speleothems, scientists can reconstruct climate changes over hundreds of thousands of years, often at high resolution, providing key evidence about past monsoons, droughts, and ice age cycles.

Why are karst areas especially vulnerable to pollution?

Karst terrains have thin soils, open fractures, sinkholes, and underground channels that allow water to travel quickly from the surface into the aquifer with little natural filtration. Contaminants from sources such as agriculture, septic systems, mining, and industrial spills can move rapidly through these pathways and emerge at springs or wells used for drinking water. Because flow is often fast and difficult to predict, cleaning up pollution in karst is technically challenging and sometimes impossible.

Are sinkholes always a sign that the ground is unsafe to live on?

Sinkholes are natural features in many karst regions, but their presence does not automatically mean an area is unsafe. Some sinkholes are stable and long‑standing, while others can form or collapse suddenly when natural cavities are enlarged or when human activities alter drainage and groundwater levels. Land use planning, site investigations, and geotechnical studies are important in karst areas to assess specific risks rather than assuming all sinkholes pose the same hazard.

What basic practices help protect bats and other wildlife when visiting caves?

Responsible cave visitation includes keeping noise and light to a minimum, staying on established paths or tour routes, and never touching or disturbing bats or other animals. Visitors should avoid entering caves where bats are hibernating or raising young, follow decontamination guidelines to reduce the spread of diseases such as white‑nose syndrome, and refrain from leaving food or trash that could alter cave ecosystems. Many agencies recommend visiting only managed or permitted caves so that wildlife protection measures are in place and enforced.