Visit the ruins of El Campamento de Can Blai
The ruins at El Campamento de Can Blai shine a light on Formentera’s Roman past. Dating back to the 2nd century BC, these crumbling rocks, 15 minutes from San Francisco, are what’s left of a defensive fortress, which was built to protect Formentera and Ibiza from invasion. While you’re here you’ll see the remains of five great towers, which were used for surveillance.