This interactive map visualizes a database of Christian baptisteries built between the 3rd and 12th centuries. The database is a digital adaptation and formalization of the most complete (as of 2017) catalogue of baptisteries by Sebastian Ristow (Frühchristliche Baptisterien, Münster: Aschendorffsche Verlagsbuchhandlung, 1998) and was compiled by Hana Hořínková in the framework of her B.A. thesis at Masaryk University’s Department for the Study of Religions (2017), supervised by David Zbíral. The map was conceived and created by Adam Mertel (Masaryk University, Department of Geography).