Trikala Castle, Byzantine fortress in Trikala, Greece

Trikala Castle is a Byzantine fortress built on a hilltop with three fortification levels, featuring four large defensive towers and polygonal exterior walls with multiple turrets. The structure rises in tiers up the slope, creating distinct separated areas at different elevations.

Emperor Justinian I built the fortress in the 6th century on the ruins of ancient Trikke, with major renovations during the 14th-century Palaiologan period. Medieval rebuilding later modified the original Byzantine structure significantly.

The castle's name survives in the Turkish designation Its Kale for the inner fortress, the corner protected by four large towers. The citadel was the centre of Ottoman administration in Thessaly, and the Clock Tower on its eastern side was first erected by the Ottomans in the mid-17th century, destroyed by the Germans in World War II and rebuilt after the war.

The castle entrance sits on the west side accessible through a semicircular stone archway, while the east side has a café with stone steps for rest breaks. Wear comfortable shoes for the climb since many paths and stairs are steep in places.

The castle's inner enceinte, on the northeastern corner, carries the Turkish name Its Kale and is guarded by four particularly large and tall towers. The archaeologist Krystallo Mantzana describes the whole complex as a typical Byzantine fortification, elongated along a southwest-to-north axis and reinforced with square towers.