Ciudad Juárez sits directly across the Rio Grande from El Paso, Texas, making it one of the busiest border crossings in the Americas. The city has a complicated reputation — the drug violence of the late 2000s and early 2010s made it one of the most dangerous cities in the world, and while security has improved significantly since then, it is still not a place for aimless wandering.
That said, Juárez has a real city underneath the headlines. The Misión de Guadalupe, founded in 1659, predates the international border by nearly two centuries. The Catedral de Ciudad Juárez faces the main plaza with a calm dignity that the surrounding streets often lack. Avenida Juárez near the bridge has markets and street food worth exploring, and the city's burrito culture is arguably the original — the burrito is said to have been invented here. The Museo de la Revolución en la Frontera, in the old Customs House, covers the city's decisive role in the Mexican Revolution of 1910, when the Battle of Juárez toppled a 35-year dictatorship and the peace treaty was signed in this very building.
If you are crossing from El Paso, keep your wits about you and stick to the main commercial areas. The walk from the Puente Paso del Norte to the cathedral and back is straightforward and generally safe during daylight hours.