Data of the CROWN Challenge, including the training data, manual annotations, and additional manual annotations. The purpose of this challenge was to compare automatic methods for classification of the circle of Willis configuration and quantification of the CoW major artery diameters and bifurcation angles on 3D time-of-flight Magnetic Resonance Angiography (TOF-MRA) images. The challenge is currently closed for new submissions, but the test data is available for download. Further information on the challenge can be found on: https://crown.isi.uu.nl/.