Blazon: Per quarterly, I or a holly branch proper fructed gules; II gules issuant from three bars wavy in base argent a castle proper between two serpents’ heads or respectant issuant from the sides of the shield; III vert on a bridge over water barry wavy in base argent and azure, two towers of the second, the dexter flying a flag of the last a saltire gules and the sinister supporting a ladder of the same; IV argent a cross of Santiago gules; overall in the fess point an escutcheon argent seven crowns 2, 2, 2, and 1 proper
The first quarter is evidently canting, acebo meaning “holly” in Spanish. The second and third quarters are apparently connected to the first lord of the town, Gaspar Ramírez de Vargas. I’m not entirely clear on whether they’re his family arms, or connected to him in some other way. (It’s unclear whether the snakes are related to The Mystery of the Snake Cauldrons, but probably not.) The seven crowns in the escutcheon are a reference to a mythical medieval battle that ostensibly took place at the nearby castle of Sicuendes, where seven counts were killed.