This conference aims to bring together disparate communities in quantum gravity and quantum information to discuss common foundational concepts, which are defined and employed in different ways across fields. Central topics will include the notions of observers and causality, but the scope extends to related ideas such as measurements, quantum reference frames, quantum groups, and more.

We will address questions such as:

• What structures are required to define observers in quantum gravity?
• What is the relation among the notions of observers, observables, and measurements?
• Which features of causal structure are genuinely new in quantum gravity compared to classical spacetime?
• Which other fundamental concepts should be examined to help build a shared conceptual language?