Madrid is one of some 340 European cities that since 2005 have been setting aside one evening a year to host a series of open-house events to mark European Researchers Night. Aimed at raising awareness and interest in science among the public at large, the initiative is being organized by the Madrid regional authority, through its department of Research and Innovation, and coordinated by the Madri+d Foundation.

Each year the CNIO welcomes people of all ages for an all-night session in which they can carry out their own experiments, learn about the day-to-day procedures involved in cancer research and even get to chat with some of its most skillful practitioners who will be happy to field your questions over a “speed dating” platform. There’s just one question that nobody knows how to answer. Who has the most fun, the visitors or the scientists?