The Umayyad Mosque in Damascus stands on a site sacred to multiple religions since at least 1000 BCE. Romans built a temple to Jupiter here. Byzantines converted it to the Cathedral of John the Baptist in the fourth century. The Umayyad caliph al-Walid I demolished the church between 706 and 715 CE and constructed the mosque that remains. The prayer hall measures 136 meters by 37 meters. The interior contains a shrine said to hold the head of John the Baptist, venerated by both Muslims and Christians. Three minarets mark the corners, the oldest from 1092 CE. Mosaics covering approximately 4,000 square meters of wall surface depict landscapes and architecture with no human or animal figures, following Islamic artistic tradition. The courtyard includes Roman-era columns repurposed from the Jupiter temple.
Palmyra sits 215 kilometers northeast of Damascus in the Syrian Desert. The city controlled trade routes between the Mediterranean and Mesopotamia from the first century BCE through the third century CE. Queen Zenobia ruled from Palmyra between 267 and 272 CE, briefly establishing an independent empire before Roman emperor Aurelian reconquered it. The Temple of Bel, completed in 32 CE, measured 205 meters by 210 meters within its enclosure. The Great Colonnade stretched 1,100 meters through the city center, flanked by columns 17 meters high. The Valley of the Tombs contains tower tombs four to five stories tall, the tallest being the Tower of Elahbel from 103 CE. Islamic State forces occupied Palmyra twice between 2015 and 2017, destroying the Temple of Bel, the Temple of Baalshamin, the Arch of Triumph, and several tower tombs with explosives.
The Ancient City of Aleppo received UNESCO World Heritage designation in 1986. The Citadel of Aleppo occupies a tell rising 50 meters above the surrounding city. Archaeological evidence shows continuous fortification since the third millennium BCE. The current structure reflects primarily Ayyubid construction from the twelfth and thirteenth centuries under rulers az-Zahir Ghazi and an-Nasir Yusuf. The entrance gate, completed in 1213, includes a bridge crossing a moat carved into bedrock. The Great Mosque of Aleppo dates to 715 CE with a minaret completed in 1090. Fighting during the Syrian civil war from 2012 to 2016 destroyed approximately 60 percent of the Old City. The minaret of the Great Mosque collapsed in April 2013. The souk, comprising covered markets stretching 13 kilometers, burned extensively in September 2012.
Crac des Chevaliers stands 65 kilometers west of Homs. The Knights Hospitaller occupied this Crusader castle from 1142 to 1271. The fortress covers approximately 30,000 square meters with concentric walls, the outer wall punctuated by thirteen towers. The inner ward contains a chapel, great hall, and storage facilities designed to support a garrison of 2,000 for five years without resupply. Mamluk sultan Baibars captured the castle in 1271 after a siege lasting one month. T.E. Lawrence visited in 1909 and called it "perhaps the best preserved and most wholly admirable castle in the world" in a letter. The structure withstood earthquakes in 1157, 1170, and 1202. Syrian government and opposition forces exchanged artillery fire around the castle between 2012 and 2014, damaging the inner chapel and several towers.
Bosra lies 140 kilometers south of Damascus near the Jordanian border. The city served as capital of the Roman province of Arabia Petraea after 106 CE. The Roman theatre, built in the second century CE under the Antonine dynasty, seats 15,000 spectators across 37 rows. The stage building stands 22 meters high with three stories. Ayyubid fortifications built around the theatre between the twelfth and thirteenth centuries preserved it. The stage wall and seating tiers remain largely intact. The ruins include a nymphaeum, baths, a triumphal arch, and gates from the city's Roman-era walls. The basalt stone used throughout construction gives the site a distinctive dark appearance.
The Dead Cities comprise approximately 700 abandoned settlements in northwestern Syria between Aleppo and Idlib. These villages flourished between the first and seventh centuries CE, supported by olive oil production and agriculture. The Church of Saint Simeon Stylites at Qalat Samaan, completed in 490 CE, marks the location where Simeon lived atop a pillar for 37 years until his death in 459 CE. The church complex formed a cross plan with four basilicas radiating from an octagonal central court that enclosed the pillar. The structure measured 90 meters on each arm. The ruins include houses, churches, monasteries, public baths, and olive presses built from limestone. Population declined after the seventh century due to economic changes and the Islamic conquest. UNESCO designated forty villages as World Heritage sites in 2011.