In 1968, Italian Franciscan fathers Virgilio Corbo and Stanislao Loffreda started excavating a large, monumental building on the northern shore of the Lake of Galilee, at a site called Capernaum. Guided by discoveries made at this site some twenty years before, the friars were hoping to fully uncover the remains of a synagogue where Jesus had ministered and healed the man who was possessed by an unclean spirit (Mark 1:21-27). The excavations ran smoothly, and before long, the basilica-shaped synagogue was completely exposed. The building consisted of a main hall and three side aisles with two rows of seven columns running north-south, and a transverse row of two columns in the north. Three door openings in the southern wall gave access into the building and another opening in the northern wall led into a small side room. A last opening in the eastern wall led to a large, colonnaded courtyard with a stone pavement. Inside the building, two tiers of benches ran along the eastern and western walls. Two platforms could also be discerned, flanking the central entrance in the southern wall. The floor of the building was covered in stone slabs of which patches were preserved intermittently. The excavators followed Kohl’s and Watzinger’s classification and labeled it a typical example of the so-called “Galilean synagogues”: basilical in shape (that is, the building is longer than it is wide), with platforms for the Torah shrine and bemah (also spelled bema, or bimah) against the wall facing Jerusalem, and a paved stone floor without mosaics. Nothing seemed out of the ordinary. That is, until the excavators started digging under the floor of the building.
Over the course of the following 12 years, the excavators collected approximately 24 000 coins from under the pavement of the hall and the courtyard of the synagogue, as well as from under the benches inside the building. Most of the coins were small in size, made of bronze, and ranged in date from the 2nd century BCE to the end of the 5th century CE. Some of the coins were found in clusters, but most were dispersed over a larger area, as if somebody had scattered them haphazardly. Five gold coins of the late 7th century were also discovered, hidden behind the benches running along the eastern wall.
The excavators were baffled by this discovery: what was going on here? Why were thousands of coins deposited under this building? Were they accidental losses, unintentionally dropped by the builders, or were they placed in the building for a certain purpose? If so, what purpose? How could they explain this phenomenon?
Over the course of the following decades, the mystery continued as archaeologists slowly started to find more and more coin deposits tucked away in ancient synagogues. In 1972, thousands of bronze coins were uncovered in the apse area of the synagogue at ‘En Gedi, adjacent to the Dead Sea. In 1977, a couple of hundred coins were found hidden in two cooking pots in a side room of the synagogue at Gush Halav in Upper Galilee. In 1978, hundreds of bronze coins were discovered under the pavement just outside the main entrance to the synagogue at ‘En Nashut in the Golan Heights. By the turn of the 21st century, a list of over twenty ancient synagogues could be generated in which at least fifty coins had been discovered, either hidden inside the building or buried immediately next to it. It could no longer be said that Capernaum was a unicum. Something larger seemed to be at hand: a phenomenon of hiding coins in synagogue buildings that was inter-regional and occurred over many centuries.
 Corbo and Loffreda published the excavations of Capernaum in a series of articles and books, written between 1968 and 2008. For a full list of publications by the Franciscan Custody, see https://www.edizioniterrasanta.it/en/?st2=cafarnao. See also the bibliography for works written on Capernaum by V. Corbo, S. Loffreda, and A. Spijkerman.
 The first preliminary excavations at Capernaum were conducted in 1905 by the Deutsche Orient Gesellschaft, directed by H. Kohl and C. Watzinger (Kohl and Watzinger, 1916, Antike Synagogen in Galilean). The Franciscan Custody of the Holy Land took over the excavations in 1907 and published their first excavation report mentioning the synagogue in 1922 (Orfali, 1922, Caphernaüm et ses Ruines).
 For a history of “Galilean synagogues” and how they compare to other synagogue types, see “The ancient synagogue and its components”
 It must be noted that not all the pavement was removed during the excavations. The excavators only opened about fourteen trenches inside the main hall and in the eastern courtyard of the building. Thus, it can be assumed that many more coins remain hidden under the building’s floor.