Lastly, there are certain islands in which these monuments are found, which do not seem to have produced any wealth of the type required, notably Sardinia and Malta. We have also an isolated group near Taranto. It seems probable that such islands, and points _en route_ with good harbours like Taranto, would have been convenient points of call to these traders, as Tarentum was afterwards to the Phœnician and Greek merchants. Here, and perhaps too at Syracuse, they may well have had depôts, but from the wealth of its megalithic monuments we may well believe that Malta was the base of operations for the western and northern trade. Here we have a small island, very isolated and with excellent ports, with a population primitive and docile; such a spot would be a safe depôt in which to collect and store valuable merchandise, until it was convenient to ship it through the more traversed and perhaps pirate-infested seas of the east. Thus, though there are more exceptions to his rule than Perry would lead us to suspect, these exceptions do not seem to weaken his hypothesis, but rather help to prove the rule. Now in Britain and the north generally these monuments, or at any rate some of them such as dolmens and long barrows, are believed to date from the neolithic age, albeit from its latest phases; nevertheless there are instances in Scandinavia and Brittany of the discovery of copper tools and gold beads in these tombs.[140] Further south the evidence of metal in association with them is clearer, but in Malta the only bronze implements discovered, the hoard found in 1915 in the temple of Hal Tarxien,[141] had been deposited above three feet of silt which had accumulated on the temple floor. This at first sight seems to militate against the theory that these structures were the tombs and temples of miners.