Open Day De Stal

In the heart of the Leiden Bio Science Park, you’ll find Grand Café De Stal – the former stable of Herman the bull, the world’s first genetically modified bull.
Although the experiment didn’t achieve its intended results, Herman remains a symbol of scientific progress and can still be seen at Naturalis Biodiversity Center.
Today, Grand Café De Stal is a cozy spot for coffee, tea, and treats. It’s also a learning workplace operated by DZB Leiden, where people seeking employment gain experience under the guidance of skilled mentors.

During the Open Day, several partners will offer fun activities for all ages!

Municipality of Leiden – ongoing

The Leiden Bio Science Park is developing rapidly. Curious about its future plans? Drop by De Stal to find out more!

De Keet – ongoing

Keet is cool, and Keet is green. At Keet, you can cycle to make your own coffee, get tips on how to help keep Leiden cool, and learn about local plants and animals. Want to meet Keet? You can – Keet will be touring again in 2025!

To keep Leiden livable, we must adapt to a changing climate, with heavier rainfall and longer hot, dry periods. We’re responding in many ways: adding more greenery to cool the city, absorb water, and support wildlife. We’re also installing separate sewage systems to ensure only dirty water goes to treatment plants while rainwater flows into canals and ditches. We use permeable paving stones and improve habitats for local plants and animals.

Keet showcases what the city is doing – and what residents can do – to help keep Leiden livable.

You’ll find information on:

• Rain barrels
• The Groene Stad 071 platform
• Green roofs and available subsidies
• Starting a neighborhood vegetable garden
• Volunteering to pick up litter (email: afvalcoach@leiden.nl)
• Façade gardens and tree pit planting
• Separate sewage systems
• How to green just 1 square meter of your garden

Psychology Lab on Wheels – ongoing

Leiden University brings science to the people with the Psychology Lab on Wheels! From our transformed research bus, visitors of all ages can take part in short experiments, discover what your eyes reveal through eye-tracking, measure your heartbeat, and learn how science — and you — work.

We offer interactive demos, share surprising insights on topics like emotion, love, and discrimination, and engage in conversation.

We aim to show: science isn’t just educational — it’s also great fun!

The Lab on Wheels is part of the comparative psychology research group that not only looks at humans, but also great apes! During the Open Day you can participate in an experiment just like the orangutans and chimpanzees do and see how you compare. Next to that we will also show how we transform our finding into useful tools by creating an app for emotions! This is how we can show: science is not on

Naturalis species safari – ongoing

Naturalis is the national biodiversity research institute. Every day, these scientists are committed to describing, understanding and conserving biodiversity. During the Open Day, they have several activities!

How many species of plants, animals and fungi live in Leiden? Go on a species safari with Naturalis. Using landing nets, magnifying glasses and determination cards, we map species around the museum. Will you join us?

The activity is continuous from 11:00 – 15:00, registration is not necessary.

Pop choir Goed Gestemd – From 12:30 to 13:30

Come and listen to Pop Choir Goed Gestemd! An enthusiastic pop choir from Voorhout with 70 passionate members on stage, accompanied by our very own “Alsjemaargoedgestemdband” (As-long-as-we’re-in-tune-band), who have supported us musically for years and help make us a true pop choir.

Our conductor, Leendert-Jan Veldhuyzen, has been leading us for 13 years and writes all our arrangements. With full dedication, he guides us through our varied repertoire. We perform a cheerful selection of songs in various languages and enjoy every note we sing. We’re always grateful for our enthusiastic and diverse audience – that’s what we do it for! We hope to continue gracing many stages for years to come with our music and to entertain audiences everywhere.

More information about our choir: www.popkoorgoedgestemd.com