Near the south door is the Chapel of Our Lady of seven sorrows, founded in 1516 by Antoine de Montécuto, Margaret's confessor and almoner. A fine painting on a wooden panel, by a Flemish artist, hangs over the altar, and was one of the sacred pictures sent by Margaret from Flanders. On the ground outside the church is a curious sun-dial, composed of twenty-four stones arranged in a huge oval, on which are engraved numbers from one to twenty-four, representing the hours of the day. In the centre of the oval are twelve stones arranged in two rows of six each, bearing the initial letters of the twelve months of the year. In order to tell the time, the spectator must stand on the letter of the current month, and his shadow then falls on the hour of the day, he himself being the index. This interesting dial dates from the building of the church, and was probably made for the use of the workmen. It was formerly placed a little further from the edifice, and composed of tiles, but, as it was in danger of being worn away by the constant traffic which passed over it, Lalande had it moved nearer to the church, and the worn tiles replaced by slabs of stone, but carefully preserved the original size and dimensions of the dial.

When Francis I. visited Brou on the 1st of October 1541, he was struck by the unique beauty of the church, though he observed that the white stone of which it was built was too soft to stand frost, and would in time crumble away. Paradin, in his Chronique de Savoie, mentions the king's visit:—'Je me souviens aussi,' he says, 'avoir veu descendre le feu roy François, quand il vint à Bourg, qui après avoir veu cette esglise restoit ravy en admiration, disant n'avoir veu ny savoir temple de telle excellence, pour ce qu'il contenoit. Vray est qu'il se print garde (comme il esttoit prince excédant en bon esprit tous les rois de son temps) que ceste pierre blanche, dont est l'esglise bastie, ne seroit de durée à la gelée, pour estre trop rare et tendre. Et s'est trouvé depuis qu'il disoit vray: car long temps après, tombèrent du quarré du clochier aucuns de ses grans bastions ou gargoles, qui conduisent les eaues sur le couvert de l'esglise, du costé des cloistres, chose qui fit grand dommage au bastiment.'

On the 17th of September 1856 (326 years after Margaret's death) the entrance to the vault at Brou was accidentally discovered in raising some flagstones near Philibert's monument, and on December the 1st of the same year it was opened in the presence of a committee of ten persons. Count E. de Quinsonas, who was present, gives an interesting account of the visit of inspection. The vault, which had not been opened since Margaret's coffin had been placed there in 1532, was entered by a flight of steps from the choir. The three coffins were found exactly under their respective monuments in the church above; Duke Philibert of Savoy's in the centre, Margaret of Bourbon's on the right, and Margaret of Austria's on the left. Philibert's coffin was intact, and of a great length, but those of the two princesses had broken open, and their remains were scattered on the floor of the vault. The three coffins rested on iron trestles.

Margaret of Bourbon's coffin was of lead, shaped like an elongated square, but had originally had an outer coffin of oak, the remains of which lay on the ground. The princess's skull was intact, and showed a tress of chestnut hair. The inscription on the leaden coffin was in French as follows:—

IHS MARIA S

Marguerite de Bourbon
1483
ce 27 Avril fut esevelie.

Philibert's coffin was found in a perfect state of preservation, in shape similar to that of Margaret of Bourbon, but of gigantic size. The duke's body had been placed in an oaken coffin enclosed in lead, which probably accounted for its preservation; whilst the two princesses had been laid first in lead and then in oaken shells, the outer cases of which had rotted away from the damp, and the inner coffins had broken open. The following is the inscription on Duke Philibert's coffin:—

✠ IHS MARIA S

Cy gist, tres excellent et tres puissant prince Philibert.
Due de Savoye IIe de ce nom. tres vertueux le quel
trespassa et rēdist lesperit a Dieu lā mil Ve et
quatre le Xe jour de Septembre au chasteau
du Pont Deyns et fust enterre ceans le
XVIe du dit mois. pries Ntre
Seignr pour luy.

Margaret of Austria's leaden coffin had also originally been enclosed in one of oak, and was shaped like a mummy case to the form of the body. The inscription on the coffin was as follows:—