One of the unexpected pleasures of a visit to the Mexican resort city of Puerto Vallarta is the Museo Histórico Naval, or naval museum. Few tourist books or maps mention it, but the white, two-story building occupies a beautiful central location overlooking the beach, less than half a block from city hall. A nearby landmark is the four arches on the Malecón, the paved seaside boardwalk that thousands of residents and tourists enjoy.