Dura
Europos
Dura Europos in Syria was founded by Alexander's lieutenant, Seleucus Nicator. The town was closely linked with Palmyra, serving as an important forward line of defense against Persians. It was captured and destroyed by the Sassanids in 256 AD shortly before the fall of the Syrian Metropolis itself.
The site did not attract significant attention until 1921, when mural paintings were discovered, notably frescoes dating from 235 AD which were in a remarkable state of preservation.

From Web syllabus for History
of Western Architecture at the University of Pittsburgh

From the Judaica
Collection at Sterling Memorial Library
Home
Worship of the Early Christians
In the 1920's archaeologists
working in present-day Syria uncovered in the desert sands a Roman garrison
town, Dura Europos; once located at the edge of the Persian empire of the
Sassanids.
In 256 A.D. the Persians laid siege to the town. The desperate inhabitants
attempted defend their town by piling mounds of dirt against the walls. In doing
so, houses next to the west wall were buried and thus preserved for the
archaeologist who uncovered them, almost 1700 years later.
The archaeologist discovered that three of the covered homes had been renovated
for use as religious buildings. One had become a Mithraeum, dedicated to the
worship of the god Mithras. Another had undergone structural modifications to
become a Jewish synagogue. The third home had been converted to a Christian
church. This Christian church is especially important as it is the earliest
complete church extant.

An examination of the
remains yields much about the liturgy of the early Christian church.
A typical Roman upper class house was centered around a columned courtyard with
an open room, atrium . In the center of the courtyard was a pool, impluvium
. At the opposite end from the entrance was a raised area tablinum
containing a table and used by the family as a reception area and for ceremonial
functions.
In the Dura Europos home converted to a church, scholars speculate that the
congregation gathered around the pool, which was used for baptism. In the tablinum
sat the bishop, who presided over the Eucharist, celebrated at the table. This
arrangement provides a logical basis for the liturgical arrangement of later
basilica churches.