The Tarxien Temples are one of Malta's great prehistoric sites, a megalithic temple complex with carved stone blocks, altars, and traces of ritual architecture older than the pyramids. Though surrounded by modern streets, the site opens a door into the island's deepest human history.
It is easy to visit from Valletta and pairs naturally with the Hypogeum, though each site has a different feel. Go with enough background to appreciate the carvings and the extraordinary age of the place.