Martelo is a shallow rock formation near Ponta da Piedade, set in a sheltered corner of the Lagos coastline. The profile is straightforward and photogenic, which makes it a strong fit for training dives and relaxed guided outings. Expect rocky relief, small crevices, and plenty of easy macro interest rather than a long swim or deep drop. It is the kind of dive that rewards calm water, tidy buoyancy, and a slow pace.