When you stand on the south-facing fortified walls of Valletta, Malta's capital city, Fort St Angelo ⛫ is what captures your attention. A little to the West, across the creek, the city of Senglea is just as noteworthy.
If you're planning a trip to Malta and fancy visiting the oldest prehistoric temple that is completely underground, I would highly recommend a visit to the Hypogeum of Hal-Saflieni in the southern part of the island.