The ever-increasing accuracy of quantum chemical calculations calls for subtle experimental benchmarks to test their systematic performance. This can be achieved in many ways, such as blind test challenges. Hereby, theoretical groups are called to reproduce an experimental observation without the bias of knowing beforehand the target result. The latter allows for constructive joint efforts, and sometimes surprising findings. The data can also be later combined in benchmark sets, which can then be repeatedly used to fine tune theoretical methods. Both are useful endeavours which we aim to promote on this page. The data collection and challenges are organised by the Faculty of Chemistry at the University of Göttingen.