The chances that you remember the last time you held some soil in your hands and truly observed it are probably slim to none. As we say in The Netherlands, it’s time to get "met de voeten in de klei". Translation: time to get your feet going, your hands dirty, and your nose activated to dive into the fascinating world beneath your feet!

Welcome to The Dirty Challenge, a team-based competition where art, science, and messy fun come together in a series of soil-centric activities. 

How it works: You and your team (or a few strangers who won't stay strangers for long) go head-to-head in a series of surprisingly insightful challenges. How are your observations skills on nature around you? Can you run experiments that actually tell you something about your soil? Do you have a worm-counting strategy? Every game gives your team a chance to get points, and, yes, there will be a prize for the dirtiest hands.

Who's this for? Friends who want to try something different. Teams of coworkers seeking to disconnect from their laptops and desk chairs. Solo adventurers who aren't afraid to get messy with new people. Even families, if your kids think you've gotten boring. There’s something for everyone, no experience needed!

What to expect? 

• Have fun with your crowd or meet new people: Join us, make a new friend or two, and enjoy a lively afternoon of connection.
• Enjoy an interactive and surprisingly educational competition: the challenge is designed to spark your curiosity and sense of wonder. 
• Take a Soil Survival Guide home: Practical tips and insights you can apply directly on your garden or house plants.
• Leave with a transformative perspective on soil: After digging up the complex layers around soil, we bet you will never look at it the same way!

Practical stuff:

When? 6th June 2026, from 2pm-5pm

At what time? Doors open at 1:45pm to kick off at 2pm.

Where? The field, Leiden

Price: 45€ per ticket. Early birds (38€) and group (team of 5= 200€) discounts available.

Limited spots available, sign up now! 

The minds behind the challenge:

Valeria is a microbiologist and underground explorer. Obsessed with the quirky behaviours of soil creatures, she's already converted her friends, her family, and several confused neighbors to soil lovers. Now she's coming for you. 

Ireth is a biophysicist in absolute awe for the tiniest soil microbes. She goes on microscopic safaris as a hobby, makes compost for fun, and heals soils as a career. 

Together, we decided lab coats and academic papers weren’t reaching enough people. So we traded them for shovels and bad jokes, in order to bring soil from sterile rooms, out into our messy reality. 

Questions, concerns, or just want to share your favorite soil fact? Email us at workshops@soilup.earth  or text +31 6 26002530.