Photographs of Leen in Leiden a receiving his PhD degree (2007) b in his office (1998) c in the wet “Coelenterata” collection with Yosphine Tuti from Indonesia (2013) d as co-supervisor of Kaveh Samimi-Namin (2016) e with Jayasree Vennam from India and Prof. Willem Vervoort (1990) f in his office with Asako Matsumoto from Japan (2012). Photograph credits a Jacques van Ofwegen b unknown c author d Livia Oliveira e unknown f Bastian Reijnen.