We all know smoking is bad for our health. But we might not have known that the cigarette filters that litter our streets also impact the environment. Esther Kentin is a lecturer at Leiden Law School. She is raising awareness of the University’s cigarette butt problem.

Every Sunday you can help fish plastic and other floating garbage out of the Leiden canals. You can use your own canoe or loan one from Plastic Spotter and join the garbage-fishing fleet. Annetje Ottow, President of Leiden University, was one of the crew on Sunday 4 July.

In the Port of Rotterdam, tiny industrial pellets leak into the environment, causing a form of pollution that’s hard to trace but highly persistent. Three students of the LDE Sustainability Honours Programme took on the challenge to identify sources of this pollution.

Lecture, Studium Generale

The university is launching a campaign to focus extra attention on our smoke-free university locations. The University is using aptly named cigarette barrels to try to show clearly just how many cigarette filters are being saved from the environment. How harmful are these cigarette filters to the e…

Nanoplastics can accumulate in developing hearts, according to a study by biologist Meiru Wang from Leiden University. Her research on chicken embryos sheds new light on how these tiny plastic particles pose a threat to our health.

Arts and leisure, Arts and leisure

Gain the knowledge and skills you need to make an impact on sustainability issues.

Some thirty Leiden students balanced on SUP boards for the Supping for Sustainability Lustrum activity. Together with alumnus Merijn Tinga, better known as the Plastic Soup Surfer, they paddled their boards through the Leiden canals and waterways, fishing plastic waste out of the water.

Purple clothing and a pride flag flying from all University buildings: Leiden University is once again taking part in Purple Friday. How do people experience this day? We asked some employees and students of the Faculty of Humanities.

Cornald Maas was able to ‘pioneer’ in Leiden. This Dutch Studies graduate, presenter, programme maker and publicist combined an active student life with studying hard.

Life returned to something resembling normal after Covid but other crises soon took its place. These great challenges are also being felt at the University and our researchers are working on solutions. The nitrogen crisis, problems with young people’s services and an increasingly urgent climate crisis:…

In a world beset with war, climate problems and skyrocketing energy prices, it is good to have some 'slack time' now and then. That was Dean Mark Rutgers' message at the Faculty of Humanities' New Year reception.

When university lecturer Martine Bruil was on exchange in Ecuador as a teenager, she fell in love with the area's ancient languages. Now, more than 20 years later, she is starting a research project on the kinship of the language Awapit with the Quechua language that was spread by the Incas.

Facility

In recent months, the university has been running the 'Smoke-free university' campaign because of the large number of cigarette waste on and around the faculties. As part of this campaign, gatherings were held in June, September and October to draw extra attention to this waste problem.

Since 24 March, the Kamerlingh Onnes Building of the Faculty of Law has been full of hundreds of colourful jellyfish. But behind that enchanting sight is a serious message: the exhibition symbolises the loss of biodiversity in the oceans due to climate change.

Amid the many traditions of Leiden’s 3 October Festival, a relative newcomer is beginning to take hold: the Science Market. At market stalls, the people of Leiden could explore or even participate in Leiden’s research – performing an ‘operation’ in the street, for example.

What better way is there for an alderman to find out where best to put his efforts than to pay a working visit to the university? Hilbert Bredemeijer, Alderman in The Hague for Education, Sport and the Outdoor Space, paid a visit to Campus The Hague on Wednesday 6 October 2021.

Buurtlab 070 is a new Leiden University project in which residents, researchers and students from The Hague work together on climate, sustainability and biodiversity solutions. What do they expect of the lab?

In September 2025 Leiden University hosted a greatly successful academic conference "Care and the Jewish Experience" organized by the Leiden Jewish Studies Network. Among our guests and presenters were academics from many universities, many disciplines and at different stages of their academic caree…

Literature – and films and social media too – helps us understand ourselves and society. That makes literary studies an eternally modern discipline, especially if you dare to combine it with other disciplines, says Nidesh Lawtoo.

Are you curious about how the human skeleton works? Discover this and more on 3 October in Leiden and on 4 October in The Hague.

Students who also want to develop their artistic talents can take a year-long art class – Practicum Artium – at the Royal Academy of Art in The Hague. ‘I can express my creativity and am learning to approach subjects in a visual way.’

Tuesday was the opening session of the LDE Bachelor Honours Programme Sustainability. Lecturers introduced themselves, students got to know each other and it was revealed what they will do to contribute to a more sustainable world in the coming months. "I immediately feel like getting started," said…

What does the University mean for The Hague? And what are researchers and students learning from the city and its residents? The Hague city councillors visited Campus The Hague on 27 September and spoke to administrators and researchers. ‘From Schilderswijk to Benoordenhout: we are a university for…

Most people think of waste as something dirty that needs to be disposed of as soon as possible, but Olivia Yun-An Dung's dissertation aims to show that this does not always have to be the case. For this purpose, she focuses on Tzu Chi recycling in Taiwan. There, an army of elderly volunteers has been…

Taking a Bachelor’s in Security Studies while starting and running two businesses: student Mohamed Sulaiman never stops. But he wouldn’t have it any other way. PLNT The Hague entrepreneurs’ hub is a source of help and inspiration.

The course Designing Your Life helps students navigate their career pathways. As it turns out, these pathways are full of twists and turns and - as with many journeys - you only make progress once you gather the courage to take the first step.

Alumnus Rennie Roos lives and works in Indonesia. What took him there, what does he do there and what inspires him?

Lecture, Studium Generale

Exhibition

450 jaar

Arts and culture

Annetje Ottow is stepping down as President of Leiden University’s Executive Board on 1 September 2025 after almost five years in the role. She looks back at the highs and lows – and ahead to what’s next.