Lonely Planet Writer

Would you pay £10 to look at an imaginary line?

London's Royal Greenwich Observatory recently announced that in March 2011 they will start charging a £10 entrance fee to visitors wanting to see the famous meridian line that marks 0 degrees longitude. The National Maritime Museum, which oversees the site, as well as the Queen's House, the Royal Observatory Astronomy Centre, and the surrounding Greenwich Park will continue to be free.

Visitor numbers and wear and tear on the site have increased over the past decade, and the Observatory has recognized the need to charge visitors to cover the cost of maintenance and development of new exhibits. The upcoming 2012 Olympics, with the equestrian events taking place in Greenwich, will undoubtedly exacerbate the problem.

Will visitors be prepared to spend £10 to see the historic official demarcation of an arbitrarily chosen location of an imaginary line? It's not just any old line, of course, but there are roughly 20,000km of meridian line outside of the Observatory, some just steps from the short £10 section, not to mention in long stretches in France, Spain, Algeria, Mali, Burkina Faso, Ghana, Antarctica, and a small 600m length in a corner of Togo.

Not to discount the historical importance of longitude in navigation, Greenwich Mean Time as a world standard, and the scientific accomplishments of the Royal Greenwich Observatory, but is it really worth the price of admission just for this photograph?

Greenwich MeridianCongratulations: you're standing in two hemispheres.

Actually – hold the line – maybe you're not standing in two hemispheres. The Prime Meridian as used by modern geodetic reference systems is 102.5m east of the marker line. If you'd like to see the real (but still imaginary) Prime Meridian, you can do so in Greenwich Park for free just outside the Observatory grounds, anywhere along the red line in the image below - and you get to enjoy your meridian experience with the smug sense of knowing better than the crowd of people paying £10 just 5.31 arcseconds west of you.

Real Prime MeridianThe Prime Meridian as used by modern geodetic reference systems (red line)

By all means, pitch in £10 to help preserve history, explore the other interesting parts of the National Maritime Museum, all of which are considerably more interesting than the line, and take the obligatory hemisphere-straddling photo while you're there. Greenwich Park is one of London's most beautiful green spaces, and the climb up the hill is worth the effort simply for some of the best views over London, even if you have no interest in the Observatory. But if you're considering paying the admission cost just to see a line on the ground, just imagine those are your shoes in the photo above and save your cash.

[Photos: Meridian Line by Stuart Chalmers; Royal Greenwich Observatory aerial photo from Google Earth]