- Was it common for temples in ancient Greece to contain treasure like gold and silver?
- Did any famous temples contain treasure rooms?
Most certainly. The famous example is the Delphi Oracle. Everyone who wanted to ask it a question brought a gift. The gifts were held in some place in the temple (apparently open for display). Several times in history it was robbed, and once such a robbery led to a major war. There is plenty of evidence in the ancient literature that other temples were also used to store treasures. They got many gifts, especially to commemorate major military victories. Sometimes the treasures were used in emergency by a city to which the temple belonged. But Delphi temple had a very special status protected by a kind of international understanding.
One such gift, originally given to a temple to commemorate the victory at Plataea, it was a huge beautiful bronze tripod, is partially preserved to our days: the main part of it stands in the Hippodrome in the center of Istanbul, other parts are stored in museums.
According to this reference to Roman temples, from A Concise Dictionary of Greek and Roman Antiquities...
As was the case with Greek temples vast stores of treasure sacred public or private were frequently preserved in the temples of the Romans treasuries were usually cellar like cavities the immense mass of concrete which forms bulk of the podium
(my italics) This indirectly says the Greeks did store treasures, but the location described appears to be for Roman temples.