Medellín is a city of parks and plazas. A great place to begin exploring is at Parque Bolívar, which admittedly is a popular hangout for bored old men, prostitutes, and drug addicts, even during the day. Avoid the park at night. Even so, this plaza is home to Medellín's largest church, the Romanesque-styleCatedral Metropolitana, made with over 1.2 million bricks, which, according to legend, were solidified with bulls' blood. The inside of the massive cathedral is rather dim and somber. The church closes at night, but generally remains open during the day.