The area in and around Trujillo’s Parque Central offers a lovely, leafy stroll through the colonial portion of town. You’ll find the 19th-century Catedral de San Juan Bautista, a few other Spanish (and French) colonial-era buildings and, most notably, the Fortaleza Santa Bárbara. This bay-surveying fort-cum-museum is where, among other things, the aspiring but failed U.S. conqueror of Central America—William Walker—was sentenced to death by firing squad.