The oldest part of the church is the tower, dating from the middle of the 13th century. The nave is from the beginning of the 14th century, while the choir dates from the middle of the same century. There was an earlier church on the same spot, elements of which have been incorporated as building material in the presently visible church. The church is richly decorated inside with frescos dating from the Middle Ages. They depict different Christian motifs. Of the church fittings, the baptismal font (second half of 12th century) and triumphal cross (middle of the 13th century) are both medieval.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.