The chapel was once located 100m to the south, near the manor's former entrance, at a place called "Park ar Japel" It has disappeared along with the dovecote, which was reported in the sale of 1720 to Marshal Poinçonneau.
The corps de logis which contains the remains of the lower-hall and upper-hall, also has a large magnificent Gothic dormer window, made of real stone lacing, with a double projection of formed crockets, creeping foliages, and grotesques on a high roofing of the era.
With monolithic steps of two metres in length, this staircase ends at the second floor by a slender column of two finely chiselled châpiteaux (capitals) from which rise up, as a sun, the wide slabs forming the ceiling.
Finally, in keeping with the Breton tradition, a beautiful basin of three metres in diameter, in granite and of a single piece, occupies the centre of the cour d’honneur.
There are several detailed accounts of the pillage of the Manor of Mézarnou in 1594 by Yves Du Liscouët, during which he had the owner, Hervé de Parcevaux, imprisoned in the château of Brest while he looted the richly decorated manor-house from top to bottom.
The Archives départementales du Finistère contain the original complaint petition submitted by Hervé de Parcevaux in 1603 and in which the inventory of the manor is reproduced in full.
Du Liscoët is said to have carried away even crosses, chalices and ornaments from the churches of Plounéventer, Plouédern, Lanneufret and Trémaouézan, which had deposited them at the manor in the hope of protecting them from robbers who were ravaging the countryside at the time.
The manor was also visited by and occupied for a short while by the bandit-rebel La Fontenelle, who kidnapped the youngest daughter-in-law of Hervé de Parcevaux, Marie Le Chevoir, and made her his wife.