The church of Taxiarchis or Ai Stratigos at Niokastro, not far from Kastania, is one of the most significant monuments in the region. Added to the south of the small church was an impressive larger annex, formed as a stoa and used as a lateral narthex. The monument was in ruins until November 2015, with its barrel-vaulted roof having collapsed.

New evidence that has come to light during recent restoration work suggests that the church was of the domed cross-vaulted type. The stoa was carefully built, with cloisonné masonry. Its faces have impressive bilobe openings; one more zone with bilobe pseudo-windows runs along the upper part of its south side. The wall paintings of the stoa’s interior are of particular iconographic interest, including a depiction of the Holy Trinity, one of the very few examples of byzantine monumental painting. The founding inscription located to the west of its entrance states that it was decorated in 1194, with mention of emperor Isaakios II Angelos and his wife Maria (Margarita). In light of the new evidence, the church should be dated to the second half of the 12th century, i.e. slightly earlier than the construction of the stoa and its decoration. Τherefore, this is one of the earliest examples of this architectural type in byzantine church building. The type becomes popular in the next hundred years.