The fossa ovalis is visible in this chamber

The fossa ovalis is visible in the right atrium of the human heart.

Explanation:

The fossa ovalis is the oval-shaped depression present in right atrium of the human heart. It is the remaining portion of the thin fibrous sheet which covers foramen ovale, of the fetal heart, during the fetal development.

It is present at the same level of the interatrial septum, which is a wall that separates the left and the right atrium.