Raid on Yavin 4

The First Battle of Yavin IV took plave just prior to the Battle of Yavin; a legion of Stormtroopers was sent to Yavin IV to confirm a Rebel presence and to gain a foothold on the planet.

While defeating all of the Rebels by penetrating the heart of the Massassi Fighting Arena near the Great Temple, stormtroopers also attacked with AT-STs while the Rebels defended themselves with combat speeders in the vicinity outside of the arena.

This base would later be deserted during the Battle of Yavin, where all Imperials had to defend the Death Star. The last few were routed out by Rebels. After the Battle of Massassi Temple, the arena was abandoned for good.

Trivia
While the heat of battle was in the fighting arena, Imperial scout troopers stealthily advanced around the perimeter of the ancient stadium and were able to capture the opposite vehicle post. Now the other Imperials could easily raid the arena from any side, a quick defeat consequently meeting the doomed Rebels.