Guided tours of the Mnajdra Temples are being held by Heritage Malta early in the morning on Tuesday and Wednesday to mark the spring equinox.
Sunrise on the first day of each season underlines the relationship between the temples and celestial bodies.
Heritage Malta said that although it is not known for certain whether these orientations were intentional, they are so systematic that this is very probable.
In prehistoric agricultural societies, observation of the motion of the stars, the moon and sun could have been related to the changing seasons and times of planting and harvesting crops.
In a bid to provide an enhanced experience to visitors, only a limited number of tickets will be available.
Tickets can be bought from Heritage Malta's sites and museums at €15 each, €10 for members
Participants will gather next to the Ħagar Qim main entrance at 5.45 a.m.
www.heritagemalta.org