Heritage Malta will be holding a special guided tour of the Mnajdra temples on Sunday to mark the equinox.

The unique setting of the temples at Mnajdra means that during sunrise on the first day of spring, the sun's rays fall directly into the southern temple of the complex and light up the interior of the building.

This phenomenon has been observed and studied for many years. The temple builders seem to have been aware of the dependency of crops on the movement of the sun, the moon and the stars. These motions must have been used to orientate the position of the temples.

The Mnajdra temples consist of three structures, the oldest of which dates to the Ggantija phase (3600-3250 BC). The two main temple structures are oriented east and south-east respectively. Early risers who visit the temples on Sunday will appreciate the precise alignment of the temples as the sun gently appears over the horizon.

The site will be open to visitors at 6 a.m. with the tour starting after the sun has risen.

The entrance fee is Lm2 and includes admission to both Hagar Qim and Mnajdra. Children under 16 years, students and senior citizens pay Lm1.

Visitors are advised to wear warm clothing.