Heritage Malta is opening the Mnajdra Temples from 6.30 a.m. on Monday on the occasion of the winter solstice.
Tickets can be bought on the day from the temples at Lm2 per person; the price also includes a visit to the Hagar Qim temples.
Officials from Heritage Malta will be on site to provide information to visitors.
The remains of the Mnajdra Temples, which date from 3,600 to 2,500BC, lie at the foot of the hill on which are located the temples of Hagar Qim.
Sunrise of the first day of the four seasons enters into the southern temple of Mnajdra and lights up the interior of the building.
The ray of sunlight on summer solstice lights up the edge of a megalith on the left of the entrance chamber. Likewise, on the winter solstice, the sunbeam hits a twin megalith on the right of the entrance chamber.
On the Equinox days, the sunlight goes into the temple and its beam lights up the main axis of the temple.