[1] In its current form it largely dates from the Palaiologan period, where it was extensively rebuilt and remodelled.

The citadel suffered much damage during its conquest by the Ottoman Turks in 1393/4, but the city's importance as a bulwark against the restless inhabitants of the Pindus mountains and the Agrafa region, as well as being the centre of the Ottoman administration in Thessaly, meant that it was quickly repaired and strengthened.

[1] The castle is, according to the archaeologist Krystallo Mantzana, a "typical Byzantine fortification", with an elongated shape along an axis from southwest to north, strengthened by square towers.

Traces of the original Justinianian fortification have been found in the southern slopes, as well as the area of the inner citadel.

[1] On the eastern side of the castle is the Clock Tower of Trikala, originally erected in the mid-17th century by the Ottomans.