Image copyright South Downs National Park Image caption The park's dark skies are accessible to 17m people across London and the South East, ranger Dan Oakley said

The dark starlit skies of the South Downs National Park have won it special status.

The park has become the 11th site in the world to be made an international dark sky reserve by the International Dark-Sky Association (IDA).

Park ranger Dan Oakley said the south of England was under threat from losing its "last few patches of properly dark skies".

The park's new status showed they were worth protecting, he added.

Image copyright South Downs National Park Image caption About two million people live within three miles (5km) of the park

Mr Oakley said the park's skies were "remarkable" - particularly when the centre of the Milky Way rose above the south horizon.

He said: "You see the Milky Way above your head, you'll see it twinkle. You'll see the dark dust lanes that go through the Milky Way."

Image copyright South Downs National Park Image caption More than 1,300 people signed a "dark skies pledge"

The move to create the reserve saw 2,700 street lamps replaced with downward-facing LED lights.

More than 1,300 people signed a "dark skies pledge" and support came from more than 70 parish, town and county councils.

Image copyright South Downs National Park Image caption Young people are growing up with stars drowned out by lights, experts said

Dr John Mason, principal lecturer at the South Downs Planetarium, said many young people were growing up in places where night-time lighting drowned out all but the brightest stars and conserving the skies was vital.

Image copyright South Downs National Park Image caption The South Downs reserve is the second in England - after Exmoor

Rural affairs minister Rory Stewart said the park brought communities "not just an opportunity to see the English countryside at its finest, but also stars far beyond our planet."

About two million people live within three miles (5km) of the park, which has Portsmouth, Brighton, Eastbourne, Winchester and Chichester on its edge.

The 11 existing dark sky reserves include Exmoor National Park in the south west and the Brecon Beacons and Snowdonia in Wales.