This edited book comprises a selection of essays inspired by the presentations delivered during the workshop 'Open Up Museums! Prospects and challenges of Accessibility, Diversity and Inclusion', co-organised in the Spring of 2022 by three EU-funded projects – reCreating Europe, DANCING, and inDICEs, and hosted by MUSE – Museo delle Scienze, and Mart – Museo di arte moderna e contemporanea di Trento e Rovereto. In the book, academics and cultural heritage practitioners reflect on how to promote 'openness' in the cultural sector. Exploring the concepts of Accessibility, Diversity and Inclusion, they offer different views on institutions and practices, giving substance to the multifold concept of 'open' culture in museums.