Osiliana had some research done with the ground-breaking radar on several hillforts of Saaremaa: Kaarma, Pöide and Valjala. It’s too early to talk about concrete results since the data is still in the process of analyzation. Nevertheless, we can say that it has already revealed two earlier walls inside of the outer wall of Valjala that we see today. This means that this wall was strengthened twice.
Read more about it: here.
Watch the news clip (in Estonian): here.