It's worth making the 10-minute ferry journey from Cais do Sodré station in Lisbon to Cacilhas across the river. This waterfront district on the southern bank of the Tagus offers one of the most beautiful views of Lisbon and has several restaurants known for their fresh fish. That journey is made on a "cacilheiro," a single-hull ferry that does the public transportation service between the two sides of the river.
As soon as you arrive in Cacilhas, you can smell the fish being grilled, inviting you to take a break for a meal before visiting the Cristo Rei monument nearby or before an afternoon at the beach. In Rua Cândido dos Reis alone (a pedestrian street found a few feet from the ferry station), you have around 20 restaurants to choose from, most serving traditional Portuguese cuisine. On this street, you may visit the Church of Our Lady of Safe Homecoming, built in 1759 with a beautiful gilded interior and decorative tile panels.
Across the road you find a large vessel (the "D. Fernando II e Glória"), which may be visited daily except Mondays. It dates from 1843 and connected Lisbon to the Portuguese colonies in India.