Around 2400 B.C.E., life in Ireland began to change again. People started making tools out of metal instead of stone. These metalworkers might have been a new wave of immigrants bringing their craft with them, or they might have been the folks already in Ireland. Whoever they were, their metal tools were much better than stone ones.

This period is called the Bronze Age because most of these tools were made of bronze, an alloy made of copper and tin mixed together. Ireland has tons of copper, and archaeologists have found traces of many copper mines. Tin is harder to get; people might have imported it from England or possibly from Brittany in France.

Smiths shaped bronze into all kinds of objects, including axes, spearheads, and jewelry. They decorated some of these with triangles and zigzags, which gives the impression that these objects might have been more for show than for use.

Ireland also had a fair amount of gold hidden in its hills, and Bronze Age smiths used it to make some spectacular jewelry — thick bracelets and necklaces called torques, fancy hairpins, and half-moon-shaped trinkets that they probably hung around their necks. They also made disks of thin sheets of gold with hammered decoration; these are called sun-discs, and people might have worn them as jewelry, too.