A FREE exhibition and tours of Stonehenge led by experts will mark the end of the International Year of Astronomy this week.

They are intended to celebrate the five millennia of astronomical heritage at the monument.

The stones align with the Sun and Moon as they rise and set, for example at the solstices and during years when the tilt of the Moon’s orbit around the Earth makes it travel to extreme northern and southern positions in the sky.

The celebration begins this tomorrow with the opening of the From the Earth to the Universe exhibition alongside the visitor centre.

It features a series of stunning images of stars, planets, nebulae and galaxies, and runs until January 3.

From Wednesday to Saturday – as part of the run-up to the winter solstice on Monday - specialists will be on hand to offer public tours of the site and surrounding area. These will be included in the price of a normal admission ticket to the site.

The expert guides include archaeologists Andrew Lawson, Julian Richards, Mike Allen and Julie Gardner, archaeoastronomer Clive Ruggles and astronomers Mark Bailey, Mike Edmunds and Derek McNally, and International Year of Astronomy UK chairman Ian Robson.