Mnajdra
Mnajdra is a group of three megalithic temples built between about 3600 and 2500 BC in a hollow above the sea, 500 metres below Ħaġar Qim, and part of a UNESCO World Heritage Site. The lower temple is aligned with the sun: at the equinoxes the first light passes straight through its main doorway, and at the solstices it falls on the edges of stone slabs inside.
