Complex sentence: This 18 m high and 23 m wide fortress could be reached by staircases via wooden bridge through narrow double gate The powerful walls 3,30 m thick narrowing towards the top ended with crenel and five small corner towers.
Split into simpler sentences: This 18 m high, and 23 m wide fortress, could be accessed via staircases with a wooden bridge through a narrow double gate. The walls were incredibly strong, 3.3 m thick, narrowing towards the top ended with crenel and five small corner towers.