During the Iron age the working and use of iron gradually becomes evident. This is also a periodo characterised by the construction of large fortified hillforts. Walk up the hill again and you'll get to a hillfort such as those that started to appear 3000 years ago as a defense shield against other populations sweeping through the valley. A massive, solid structure of cut stones with surrounding ramparts and a watchtower, hillforts were a protected place often built in the woods and upland to better sight the enemy, even from afar.