The theme of this trail is astronomical Prague and places associated with cosmology and astronomy in the Middle Ages, the Renaissance and in early modern times. It starts at the foundations of Central European erudition, i.e. at the Karolinum and takes in that gem of mediaeval cosmology, the Prague Astronomical Clock. In the Old Town of Prague it visits the tomb of Tycho Brahe in the Tyn Church, the Prague meridian, the house U jednorožce, Betlémské náměstí square and another centre of university education, the Klementinum; leading past the house that Johannes Kepler used to live in, the trail returns to the mediaeval cosmological symbolism on the Old Town Bridge Tower. Duration approximately 3 hours.