Trikala’s castle crowns a hilltop just back from the northern side of the river, 400m west of the central squares. Although it stands on the site of Trikala’s ancient acropolis, its surviving incarnation dates from the Ottoman era. You can’t enter the castle itself or the 16th-century clock tower that’s set slightly apart, but the surrounding gardens make for a pleasant stroll, and there’s a good cafe on a terrace immediately below.