Mishnà su Ezechiele 46:22

The courtyard of the women was a hundred and thirty-five cubits long by a hundred and thirty-five wide. It had four chambers in its four corners, each of which was forty cubits. They were not roofed, and so they will be in the time to come, as it says, “Then he brought me forth into the outer court, and caused me to pass by the four corners of the court, and behold in every corner of the court there was a court. In the four corners of the court there were keturot courts” (Ezekiel 46:21-22) and keturot means that they were not roofed. For what were they used? The southeastern one was the chamber of the Nazirites where the Nazirites used to boil their shelamim and shave their hair and throw it under the pot. The northeastern one was the wood chamber where priests with physical defects used to pick out the wood which had worms, every piece with a worm in it being unfit for use on the altar. The northwestern one was the chamber of those with skin disease. The southwestern one: Rabbi Eliezer ben Jacob said: I forget what it was used for. Abba Shaul says: they used to store there wine and oil, and it was called the chamber of oil. It [the courtyard of the women] had originally been smooth [without protrusions in the walls] but subsequently they surrounded it with a balcony so that the women could look on from above while the men were below, and they should not mix together. Fifteen steps led up from it to the courtyard of Israel, corresponding to the fifteen [songs of] ascents mentioned in the Book of Psalms, and upon which the Levites used to sing. They were not rectangular but circular like the half of a threshing floor.