The Meridian Line was introduced after a meeting in 1884 to agree upon a new world standard
Visitors to the world-famous Meridian Line at the Royal Observatory in Greenwich, south-east London, are to be charged for the first time in 10 years.
Entrance to the building's courtyard, where the official line is marked, has been free since 2001.
From 8 March adults must buy £10 tickets, valid for a year, although children will not be charged.
The National Maritime Museum, which runs the site, said "wear and tear" had grown substantially in the past decade.
It had to ensure it could afford "to manage this increase safely", it added.
The museum said the extra income would also help to develop the galleries and facilities at the observatory, which features a planetarium and exhibition space.
The Meridian Line, which is at 0° longitude, was introduced after the 1884 International Meridian Conference.
It was held in the US capital, Washington, to decide the point from which time and space should be measured.
The meeting also agreed Greenwich Mean Time (GMT) would be used as a world standard.
