Muslim men line up during prayers for the muslim festival Eid al-Adha, also known as the Sacrifice Feast at Karangwan Field in Yogajakarta, Indonesia on Sept. 12, 2016. The holiday is one of the most important in the Islamic calendar and it isn't unusual for festivities to be held outdoors because most mosques can't accommodate the high attendance. Eid al-Adha honors Ibrahim’s willingness to sacrifice his son for god. After morning prayers, elder male goats and bulls are typically sacrificed. 

Two women take a selfie before the prayers begin for the muslim festival Eid al-Adha, also known as the Sacrifice Feast at Karangwan Field in Yogajakarta, Indonesia on Sept. 12, 2016. 

Muslim families arrive at Karangwan Field in Yogajakarta, Indonesia for the morning prayers.

Women find spots to sit before the prayers begin for the muslim festival Eid al-Adha at Karangwan Field in Yogajakarta, Indonesia on Sept. 12, 2016. Just as in the mosque, the field is divided into a sections by gender.

Women stand on prayer rugs during the morning prayers. Worshippers wear their best prayer robes and bring their finest rugs, which they typically place on newspapers so as not to get them dirty. 

A man discards the newspaper he placed his prayer rug on after the ceremonies.

A bull stands tied up outside the Kauman Great Mosque in Yogajakarta, Indonesia on Sept. 11, 2016, the day before Eid al-Adha. Any animal slaughtered on Eid must fit certain criteria: they must be an herbivore, an adult (typically male as females could still bare offspring and produce milk), and be devoid of any obvious defects.

A bull waits in a holding pen down the street from An ricratain Mosque in Yogajakarta, Indonesia on Sept. 12, 2016. One of the guidelines participants follow is to keep the animals as calm as possible before slaughter. This includes not slaughtering them in front of each other, and also making sure they have plenty of food and water prior to the ritual.

Men lead a bull on its final walk from a holding pen to the An ricratain Mosque where it will be slaughtered for Eid al-Adha.

A bull dies by ritualistic slaughter during the muslim festival Eid al-Adha, also known as the Sacrifice Feast on September 12, 2016 in Yogajakarta, Indonesia.

Muslim men butcher a bull and divide its meat into three parts: a portion for the family who owned or sponsored the animal, one for friends and relatives, and the third to be given to the poor, at An ricratain Mosque on Sept. 12, 2016 in Yogajakarta, Indonesia.

Discarded organs from slaughtered animals sprawl across reused banners and tarps at An ricratain Mosque on Sept. 12, 2016 in Yogajakarta, Indonesia.

Men hold a bull down during a ritualistic slaughter at An ricratain Mosque. While they try to keep the animal calm, they must also quickly wrestle the animal to its side to shorten its time of distress before death. 

A man drains holds the bull's head over a recessed pit in the ground to drain the blood and ensure the animal's death before it is butchered at An ricratain Mosque on Sept. 12, 2016 in Yogajakarta, Indonesia.

Organs from a freshly butchered bull are stuffed into a large bucket. The meat is sectioned into smaller pales for families to take home.

Men hold the bull down during a ritualistic slaughter at An ricratain Mosque for the muslim festival Eid al-Adha, also known as the Sacrifice Feast on Sept. 12, 2016 in Yogajakarta, Indonesia.

A blood draining pit at An ricratain Mosque on Sept. 12, 2016 in Yogajakarta, Indonesia. The pits are covered up most of the year and only uncovered for Eid Al Adha.

A man about to preform the slaughter for Eid Al Adha reads names of the families that contributed to buying the bull for the ritual and invokes the name of Allah at An ricratain Mosque on Sept. 12, 2016 in Yogajakarta, Indonesia. Another man holds the loose skin of the bull's throat so the process can be as quick as efficient as possible. 

Bull heads lay discarded after their ritualistic slaughter at An ricratain Mosque during the muslim festival Eid al-Adha, also known as the Sacrifice Feast on Sept. 12, 2016 in Yogajakarta, Indonesia. Tradition states that the head be removed after the animal has been confirmed dead, and not during the slaughter.

Men hold the bull down and block arterial spray with part of tarp during a ritualistic slaughter at An ricratain Mosque for the muslim festival Eid al-Adha, also known as the Sacrifice Feast on Sept. 12, 2016 in Yogajakarta, Indonesia.

A man stares out over a freshly slaughtered bull at An ricratain Mosque during the muslim festival Eid al-Adha, also known as the Sacrifice Feast on Sept. 12, 2016 in Yogajakarta, Indonesia.