An online K-12 school that supports home-schooling in many countries around the world (including Portugal!), whose accreditation makes graduates eligible for application to many universities around the world -including most of those one might consider worth attending in USA!
From AboutUs section of their website:
We believe that learning begins with curiosity. From kindergarten through 12th grade, every Clonlara student learns through an individualized, meaningful, and relevant process called Full Circle Learning. This research-supported method encourages students to formulate questions and discover answers about subjects that capture their attention, leading them to deeper understandings that they are able to share, challenge, and extend. (Source)