I want to know the answer to the following question:
When were the preserved hill forts in Estonia built?
All the background I'm provided with is that "In addition, the country has several unique, more or less preserved hill forts dating from pre-Christian times, a large number of still intact medieval castles and churches, while the countryside is still shaped by the presence of a vast number of manor houses from earlier centuries.". Is that enough to answer the question?
Answer: yes