UIS - Union Internationale de Spéléologie

17/09/2026

14/09/2026

Did you know that caves and karst landscapes provide drinking water for more than a billion people worldwide? 💧 They also cover nearly a quarter of the Earth’s land surface.

Today, we mark the first International Day of Caves and Karst, spotlighting these extraordinary environments and their vital role in supporting biodiversity, freshwater resources and our understanding of the planet’s history.

Their importance is also reflected across UNESCO-designated sites, with caves and karst features found in UNESCO Global Geoparks, and properties around the world.

Safeguarding these fragile environments means conserving a natural heritage that benefits both people and the planet. 🌍

Find out more: https://www.unesco.org/en/days/caves-and-karst?hub=180536

12/09/2026

We want to share what we experienced during the celebration of the first International Day of Caves and Karst!!

Celebration of the first International Day of Caves and Karst at Po...

12/09/2026

Today was the second day of our academic sessions. Interesting topics were presented.
Congratulations to all the participants for such amazing work!!

11/09/2026

Today, the International Day of Caves and Karst (IDCK) celebration academic program began. Attendees enjoyed their IDCK greeting bags, engaging speeches, and conferences.

09/09/2026

Today, the UIS Bureau held its annual meeting at the UIS headquarters at the Inštitut za raziskovanje krasa ZRC SAZU in Postojna, Slovenia. All current bureau members were present to discuss various UIS topics and prepare for the grand celebration of the International Day of Caves and Karst (IDCK).

Are you celebrating the IDCK with your organization? Let us know in the comments.

16/07/2026

🎉𝐈𝐧𝐯𝐢𝐭𝐚𝐭𝐢𝐨𝐧 𝐭𝐨 𝐬𝐡𝐚𝐫𝐞 𝐬𝐩𝐞𝐥𝐞𝐨𝐥𝐨𝐠𝐢𝐜𝐚𝐥 𝐞𝐯𝐞𝐧𝐭𝐬 𝐰𝐢𝐭𝐡𝐢𝐧 𝐭𝐡𝐞 𝐟𝐫𝐚𝐦𝐞𝐰𝐨𝐫𝐤 𝐨𝐟 𝐭𝐡𝐞 𝐜𝐞𝐥𝐞𝐛𝐫𝐚𝐭𝐢𝐨𝐧 𝐨𝐟 𝐈𝐧𝐭𝐞𝐫𝐧𝐚𝐭𝐢𝐨𝐧𝐚𝐥 𝐃𝐚𝐲 𝐨𝐟 𝐂𝐚𝐯𝐞𝐬 𝐚𝐧𝐝 𝐊𝐚𝐫𝐬𝐭 (𝐈𝐃𝐂𝐊)🎉

On 13 September 2026, the world will celebrate the International Day of Caves and Karst (IDCK) for the very first time following its proclamation by UNESCO.
This is a unique opportunity to raise awareness of the importance of caves and karst for water resources, biodiversity, science, cultural heritage, and sustainable development.
The official international celebration will take place in Postojna, Slovenia (10–13 September 2026).

𝐁𝐮𝐭 𝐈𝐃𝐂𝐊 𝐛𝐞𝐥𝐨𝐧𝐠𝐬 𝐭𝐨 𝐞𝐯𝐞𝐫𝐲𝐨𝐧𝐞!

We encourage all UIS Member Countries, national societies, UIS Commissions, show caves, geoparks, biosphere reserves, universities, museums, schools, protected areas, NGOs, and local communities to organize their own IDCK activities around 13 September.

Whether you organize a lecture, cave tour, exhibition, school event, clean-up campaign, or social media activity, every event helps raise awareness of caves and karst.

Please register your planned IDCK events with the UIS in the next form: https://forms.gle/dFxR45pzWpcDvQu29

After your celebration, send us a short report and a few photographs so that we can showcase IDCK activities from around the world on the UIS and IDCK websites and social media.

The International Union of Speleology wants to know how the different institutions, federations, clubs, and cavers will celebrate the first International Day of Caves and Karst. Please share your celebration plans with us, as your involvement is important in highlighting the global significance of t...

02/07/2026

📸GREAT NEWS FOR PHOTOGRAPHERS!

Due to popular demand and to give everyone a chance to capture and finalize their amazing subterranean shots, the deadline for the 2nd UIS International Karst and Cave Photography Contest has been officially extended!

New Deadline: July 15, 2026

Don't miss this opportunity to share your unique images of the underground world, from stunning cave landscapes to rare cave biology specimens.

Categories:
Cave Biology: Life and ecosystems underground.
Cave Protection & Conservation: Human impacts and preservation efforts.
Aesthetics and Creative Perspectives: Artistic visions of the dark.
General Speleology: Exploration, research, and people in caves.

Submit your photos here: https://forms.gle/UUEDrNsiQR7HPb7F7

If you prefer not to use Google, email us at [email protected]

Full Details: https://uis-speleo.org/index.php/2026/04/28/the-2nd-uis-international-speleological-and-karst-photography-contest/


Show us the invisible life and visible impacts of the darkness. Best of luck!

19/06/2026

📣 Reminder – Call for Abstracts!

Join us in Postojna, Slovenia, for the international scientific conference:

"Explore, Understand and Protect: Towards Sustainable Management of Caves and Karst", 10–13 September 2026

The conference is part of the first celebration of the UNESCO International Day of Caves and Karst (IDCK) and will bring together researchers, cave and karst experts, educators, managers, and conservation professionals from around the world.

Keynote speakers include:
• John Gunn (UK),
• Zoran Stevanović (Serbia),
• Ilias Valiakos (Greece),
• Marlene Liddle (Haida Gwaii, Canada),
• Franci Gabrovšek (Slovenia)

Abstract submission deadline extended to July 10
Registration remains open until 1 September 2026
More information: https://izrkp.zrc-sazu.si/en/dogodki/international-day-of-caves-and-karst-idck

The programme includes scientific sessions, excursions to some of Slovenia’s most important karst sites, and participation in the first official celebration of the UNESCO International Day of Caves and Karst in Postojna Cave on 12 September 2026.

IMPORTANT: Accommodation availability in Postojna is becoming limited. Participants are encouraged to register and book accommodation as early as possible. If you need assistance finding accommodation, please contact the local travel agency Kompas Postojna: https://www.kompas-postojna.si/index.html

We look forward to welcoming you to Postojna!

First celebration of the UNESCO International Day of Caves and Karst in Postojna Under the honorary patronage of the President of the Republic of Slovenia, Dr Nataša Pirc Musar, and under the patronage of UNESCO, with the support and cooperation of the Slovenian National Commission for UNESCO, Post...