Vila Franca Islet is the exposed remains of a Surtseyan volcanic cone of phreatomagmatic origin heavily eroded by the sea and seismic forces over time. It is composed mostly of basalt and palagonitic tuff, resulting in characteristic vertically fractured rock formations resembling columns.[2] The islet contains a few underwater caves.
The islet is located between 500 metres and 1 kilometre off the south-central coast of the island of São Miguel, adjacent the municipality, town, and port of Vila Franca do Campo. The semicircular islet measures approximately 5 hectares in area. The islet's highest point is approximately 62 metres above sea level. One of the islet's most notable geological formations is the 32.5 metres volcanic stack called Farilhão, which is located off the islet's southern end.
The boat tour consist to navigate around and on external side to view all parts of the islet, their sea life (like crabs, seagulls) and cory shearwater, a specie comes all year to the islet for the nest. The duration of the boat tour is 45 minutes.