Mentioning “Testaccio” and “pizza” in the same sentence elicits one typical response from locals: Da Remo, which is a Roman institution. In the summer, reservations at least 2 days in advance are wise. Every crisp-crusted pizza is made for all to see behind the open counters. The most basic ones (Margherita and Marinara) start at around 6€. If it’s too crowded on a summer evening, order your pizza as takeout and eat it in the quaint park across the street. No credit cards.