The Patras lighthouse stands at the end of the breakwater on the northern edge of the port, a working navigation light that also functions as one of the city's more pleasant waterfront walks. The lighthouse itself is a handsome 19th-century structure in the neoclassical style, and the approach along the breakwater gives good views back towards the city skyline — the castle on the hill, the dome of the Saint Andrew cathedral, and the long sweep of the waterfront.
It's not a destination in itself but pairs well with a walk along the waterfront. The port area can be noisy and busy with ferry traffic, but the breakwater is usually calm and the view from the end looking across the Gulf of Patras is worth the short walk. Early morning is the best time — the ferries are less active, the light on the water is good, and you'll have the breakwater largely to yourself. Local fishermen often work from the rocks below the lighthouse, which adds to the harbour atmosphere.