Dacian fortress of Covasna - Credit: Wikimedia Commons
The Dacian fortress of Covasna served as a Dacian fortified town and is rated to have been built in the 1st century BC. It sits on a mountain in the Brețcu-Oituz Mountains above the town of Covasna, which is 227 km from the capital of Bucharest. The fortress is also known by the name of the Fairies Fortress, sitting atop of the Valley of Fairies. Read more on Wikipedia
Source: en.wikipedia.org