Financed through NWO, the Netherlands have a 20% share in the UK/NL/E Observatorio del Roque de los Muchachos on La Palma in the Canary Islands. This includes a 4.2m optical telescope (the William Herschel Telescope/ WHT) and a 2.5m optical telescope (the Isaac Newton Telescope/ INT). The Dutch Open Telescope (DOT), a Solar Telescope is located on the same mountain site. The Dutch universities have a commitment to provide some staffing and instrumentation for these telescopes. Leiden staff frequently have spent long periods there. The Dutch participation is managed through NWO-EW. The present director is T. van der Hulst, a Dutch astronomer.