The Baptismal Font of Duke Višeslav the first Croatian Duke who reigned around 800 is one of the most important monuments of church furnishing. This hexagonal stone vessel is witness to the time when Croats were Christianised, and during the Christianisation worshippers were baptised in it. The replica, can be found in the Museum of Nin Antiquities while the original is kept in the Museum of Croatian Archeological Monuments in Split.
Around the edge of the six-sided Baptismal Font, there is an inscription which reads: „This font receives the weak to enlighten them. Here they are purged of their sins which they received from their first parent, in order to become Christians, salutary confessing the Eternal Trinity. This work was skilfully made by priest John at the time of Duke Višeslav, out of piety but to honour Saint John the Baptist, to mediate for him and his protégé“. On the font there is carved cross with a three strand plait which suggests the symbolism of the Resurrection.