Priority — in situ
Pio Monte della Misericordia
The Seven Works of Mercy (1607) is above the high altar, visible from the nave. The church is in the historic centre on Via dei Tribunali, a few minutes' walk from the Duomo and from Spaccanapoli. Opening hours are typically Monday–Saturday 09:00–14:30, but check the official site before visiting as hours vary. A small entry fee gives access to the upstairs pinacoteca, which holds seventeenth-century Neapolitan paintings and preparatory drawings. The altarpiece can be seen from the nave without paying.
Museum — essential
Museo e Real Bosco di Capodimonte
The Flagellation of Christ (c. 1607–1610) is the principal Caravaggio at Capodimonte — a large canvas, around 286 × 213 cm, painted for the De Sanctis chapel of San Domenico Maggiore and later acquired by the Bourbon royal collection. The museum also holds works from his circle and followers that help clarify the immediate Neapolitan influence of his style. Capodimonte is on a hill north of the city; allow 30–40 minutes from the historic centre by taxi or bus. The museum is large — plan at least three hours.
Secondary site
Sant'Anna dei Lombardi
A church in the Spanish Quarter area, near Piazza del Gesù Nuovo, with works attributed to Caravaggio or his close circle. Less certain in attribution than the main sites but worth including if you are spending a full day on the Neapolitan phase. The church also contains one of the finest ensembles of Renaissance sculpture in Naples, making it a useful stop regardless of the Caravaggio question.
Comparative stop
Naples as a city of Caravaggism
Caravaggio's two Neapolitan stays produced an immediate and lasting local tradition. Battistello Caracciolo, Artemisia Gentileschi (who worked in Naples from 1630), and Jusepe de Ribera all worked in or around Naples and all show the pressure of his example. Capodimonte's collection of seventeenth-century Neapolitan painting is the best place to read this transmission. The influence did not dissipate: it became the dominant register of Neapolitan sacred painting for two generations.