"The Gateway" is a crucial battleground in northern Syria, where powerful armed groups are rallying to reclaim the city from DAESH.
What is Al Bab?
Al Bab is a northern Syrian city in the country's Aleppo Province where a brutal battle has taken place since 2012. DAESH took control of the city in early 2014, turning it into one of its most important strongholds.
Several armed groups associated with the US-led coalition and Turkey aim to take the city from DAESH to have a strong position for the Aleppo fight. It's also a decisive stronghold from which to claim the rest of the north.
Why is Al Bab so crucial for the warring parties?
Al Bab, which means "the Gateway" in Arabic, is a pivotal location for the Aleppo fight because of its proximity to the city.
Aleppo was the most populous city in Syria before the war broke out. Whoever controls the city is better placed to control the fate of Syria.
Two anti-DAESH armed groups are targeting Al Bab at the same time. One is the US-backed Syrian Democratic Forces (SDF) and another is the Turkey-backed Free Syrian Army (FSA).
Al Bab is a gateway for the SDF, which is mainly led by the YPG, to reach the YPG's isolated northwestern autonomous "canton" of Afrin. In late 2013 the YPG claimed to establish three "cantons" named Afrin, Jazira and Kobane (from west to east) in northern Syria.
If the YPG can take Al Bab it will have a military corridor which will allow it to join all of its "cantons" in northern Syria.
That concerns Turkey because the YPG is affiliated with the PKK. The PKK has waged an armed struggle against Turkey for more than 30 years which has led to tens of thousands of deaths. It is recognised as a terrorist organisation by Turkey, the EU and the US.
As a result, Turkey wants FSA forces to take Al Bab to prevent the formation of a YPG corridor along its border. If the FSA captures Al Bab it will also get closer to Aleppo.
Why does Al Bab matter so much for DAESH?
Near Al Bab is a village named Dabiq, which is also the name of DAESH's online magazine. The group believes that Dabiq is one of the possible locations for a legendary battle, a war corresponding to the Bible's Armageddon, between Christians and Muslims.
The city additionally provides DAESH a vital link between areas under its control around Aleppo and territories close to Raqqa, the group's self-proclaimed capital in northeastern Syria. If it loses the city, it will also be completely disconnected from the Turkish border.
Armed groups are currently looking to strengthen their military position around Al Bab if DAESH decides to withdraw from the city.
FSA forces have approached the village of Dabiq in recent weeks. "If matters proceed as planned, within 48 hours we will be in Dabiq," a commander of Sultan Murad, one of the armed groups under the FSA, told Reuters on Monday.
Will DAESH make a last stand at Al Bab?
If DAESH is intent on staying in Syria, it will need to fight for Al Bab. If the city falls, Raqqa will be an easy target for anti-DAESH forces.
A tough battle for Al Bab lies ahead.