The enclosed Gentile court in the temple started from the outer wall of the temple mount complex to the Soreg fence inside the temple complex which no Gentile could go beyond.

(I realized that the gentiles couldn't go beyond a certain point in the temple complex, but I always thought that point was the outside wall of the temple so this is the first time I read about the Soreg fence.)

The Temple Mount - Temple Institute

This shows the temple mount complex in Jerusalem after Herod's expansion of it.

Scroll down the above link until you come to the pictures on the left of the Soreg fence  highlighted with a red line and the pictures on the right of the temple mount plaza highlighted with a red line.

"The Soreg: Those who had been rendered impure through exposure to the dead were not allowed to proceed beyond the Soreg fence, which was a low built partition,(seen in the pictures on the left inside the red line). A number of openings in the Soreg allowed for pilgrims who were permitted, to pass through."

"Gentiles were permitted to enter the Temple Mount up until the Soreg fence. Large signs made of stone were placed along the Soreg with warnings engraved on them, forbidding entry to gentiles and those who were impure. Some of these signs have been found in archaeological excavations. Written in Greek and Latin, the signs state: "The stranger may not pass the Soreg and the partition around the Temple. A stranger who enters, does so at his own risk.”