Complex sentence: The new Walls had nine gates, which were to be those of Teruel, Argén, Sopeña, Cárrica, Castellnovo, Valencia, la Maza and Altura, gates that are well documented in contemporary and later writings.
Split into simpler sentences: The new walls had nine gates, named Teruel, Argén, Sopeña, Cárrica, Castellnovo, Valencia, la Maza and Altura. These gates that are well documented in contemporary and later writings.