Petranaki arena The Petranaki arena , also known as the Arena of Justice and commonly referred to as the Geonosis execution arena , was a large structure on the planet Geonosis . It was used for Petranaki gladiatorial battles between creatures and sentient beings . Ten years after the Invasion of Naboo by the Trade Federation , the arena was the site of the attempted execution of Jedi Obi - Wan Kenobi and Anakin Skywalker and senator Padmé Amidala . A team of 200 Jedi led by Jedi Master Mace Windu was sent to the arena to rescue the trio , but were attacked by battle droid s belonging to the Confederacy of Independent Systems . Most of the Jedi were killed before being rescued by the newly formed Grand Army of the Republic , marking the beginning of the Clone Wars . Description . Located on the planet Geonosis in the desert plains near the battle droid foundries and Archduke Poggle the Lesser ' s seat of power , the Petranaki arena was a circular structure comprised of large spires built out of a natural rock hollow . The center of the arena was a flat , circular , sand floor with three columns near the edge . On the columns were chains used to keep prisoners in place during executions . It contained seating for over 100 , 000 spectators while certain viewers were able to watch the gladiatorial duels from a balcony . The arena served as a form of execution for prisoners rather than maintaining costly detention centers , and also doubled as a distraction for the native Geonosians , who often had to pay a fortune to sit in the front while enjoying lightly grilled arch grub s as a snack food . Along the base of the inside of the structure were gates that would open to release vicious creatures which either fought other creatures such as reek s , nexu s or acklay s in brutal sporting contests , or pitted beings against the fierce creatures . The arena also served as a means of displaying new military droids and weapons , and could be flooded for water battles . Keeping order in the arena were the picador s , orray - mounted Genoosians with stun poles who pulled carts of criminals into the arena , and re - established order when things got out of hand . History . Clone Wars . Ten years after the Invasion of Naboo by the Trade Federation , Geonosis was the location of massive battle droid foundries operated by the Geonosian s for use by the Confederacy of Independent Systems , a political alliance of star system s that had left the Galactic Republic . When Jedi Master Obi - Wan Kenobi was taken prisoner after discovering the foundries and the status of former Jedi Count Dooku as the leader of the Separatist movement , Jedi Anakin Skywalker and senator Padmé Amidala arrived on Geonosis and attempted to rescue him . The two were captured and sentenced to be executed in the arena along with Kenobi . The Geonosians , under the leadership of Poggle the Lesser , deployed an acklay , a reek , and a nexu to kill the trio , but the three managed to escape their chains and last long enough for a team of 200 Jedi , led by Master Mace Windu , to come to their rescue . The Jedi were attacked by battle droids belonging to the Separatists , and the majority of them perished in the battle . However , just as Dooku was ordering the droid s to finish off the remaining survivors , the newly - formed Grand Army of the Republic rescued the Jedi . This began the Battle of Geonosis , the first battle in the Clone Wars . Legacy . In the years following Galactic Empire ' s rise to power , the Empire would spin the tale of Jedi Obi - Wan Kenobi , Anakin Skywalker and Senator Padmé Amidala ' s execution as being lawful and interrupted by Mace Windu and his " criminal gang , " thus sparking the Clone Wars . Behind the scenes . Obi - Wan Kenobi ' s fight with the acklay in the 2002 film was inspired by the 1961 movie , where a shipwrecked sailer battled a giant crab . The Geonosis execution arena made an appearance in the 2002 film . It was referred to as the " Petranaki arena " for the first time in " Ultimate Star Wars " published in 2015 .