Prime Meridian

Sightseeing attraction | London | England | United Kingdom

Historical attractions in London

The Prime Meridian in London, England, is one of the most famous geographical landmarks in the world, marking the zero meridian, the imaginary line from which Earth's longitude is measured. This line, which divides the globe into eastern and western hemispheres, was officially established in 1884 at the International Meridian Conference in Washington, D.C., and runs through the Royal Observatory in Greenwich Park in southeast London. The site is not only a symbol of science and navigation but also a popular destination for visitors who want to experience a piece of world history by literally standing with one foot in each hemisphere.

Visit Royal Observatory Greenwich

The history of the Prime Meridian is closely linked to the development of modern timekeeping and navigation. In the 17th century, the Royal Observatory was founded by King Charles II to solve the "longitude problem" – one of the greatest challenges of seafaring, as ships without precise longitude determination often got lost. Astronomer Royal John Flamsteed began his work in 1675 to create the foundations for accurate star charts. Later, in the 19th century, the work of George Biddell Airy, the seventh Astronomer Royal, led to the definition of the Greenwich Meridian as the international standard. Airy's Meridian Circle, a telescope installed in 1851, marks the exact position of the zero meridian and remains a central feature of the landmark.

History and significance of Prime Meridian

The Prime Meridian itself is visually represented as a physical line in the courtyard of the Royal Observatory – a metal strip embedded in the ground, complemented by a modern laser projection that traces the line across the sky at night. Visitors can stand along this marking and take photos, making the location one of the most photographed spots in London. A large world map on the wall shows how the line passes through different countries, including France, Spain, Algeria, and all the way to the South Pole, highlighting the global significance of the zero meridian.

History of timekeeping and navigation

The Royal Observatory, home to the Prime Meridian, is an architectural highlight with a rich history. Designed by Sir Christopher Wren, the building was originally used as an astronomical observatory and now houses a museum that illuminates both the scientific past and cultural significance of the site. Exhibits include historical instruments like the Meridian Circle, telescopes, and clocks, including the famous H4 by John Harrison, which helped solve the longitude problem. The Flamsteed House area also showcases the lives of the astronomer families who lived here, providing insights into the science of the 17th and 18th centuries.

Green spaces and viewpoint in Greenwich

In addition to the zero meridian, the site also offers stunning views over London. From the hill of Greenwich Park, there is a panoramic view overlooking the River Thames, the modern skyscrapers of Canary Wharf, the O2 Arena, and historic buildings like the Queen's House. This combination of nature and city makes the location particularly appealing. The park itself, a UNESCO World Heritage site, enhances the experience with its expansive lawns, old trees, and the opportunity to explore the surroundings on foot.

The significance of the Prime Meridian extends beyond science – it is also a symbol of timekeeping. Greenwich Mean Time, the standard time emanating from here, became the basis for world time and continues to shape the global time zone structure, even though it has technically been replaced by Coordinated Universal Time. A red ball, known as the Time Ball, drops daily at 1 pm and was used in the past as a signal for sailors to synchronize their ship clocks. This historical ritual is still maintained and regularly attracts spectators.

The Prime Meridian has also left cultural traces. It inspires visitors to think about the invisible lines that structure our world and is often mentioned in literature and media. Its universal significance attracts people from around the world, from science enthusiasts to tourists to school groups, who can experience geographical fundamentals here.

Contact details

Web

Phone

Address
Royal Observatory, Blackheath Ave
SE10 8XJ London

Map view

Opening hours

Sunday10:00 - 17:00
Monday10:00 - 17:00
Tuesday10:00 - 17:00
Wednesday10:00 - 17:00
Thursday10:00 - 17:00
Friday10:00 - 17:00
Saturday10:00 - 17:00

Reviews

5760 Reviews

Nicolae Raducu
09.03.2025

Nice experiene
Alessia
08.03.2025

Sicuramente una tappa obbligatoria poco lontano dal centro di Londra (un’oretta circa coi mezzi)
Tom Price
08.03.2025

The highlight of the museum! A breathtaking landmark of global significance.
Stella Mariz Magana
05.03.2025

The zero longitude is not inside the observatory but we found it somewhere east of it. Good thing we didnt buy tickets.
MUNTZ Shamiah
03.03.2025

La pente pour y arriver est incroyable (35 ou 40 degré) mais ça en vaut la peine ne serait ce que pour le panorama
Daniel Xu
02.03.2025

Not only to explore the geography, but also the perfect location to observe the whole city of London!
Dilasha Done
01.03.2025

That was a dream come true for me to see and experience what I learned from school.
S CHOI
26.02.2025

엘리자베스 여왕의 어리시절도 알고 가시면 그 주변 분위기와 그리고 그리니치 천문대의 시대적 상황도 이해를 넘어 동화가 될것입니다
Nikos Sifakis
25.02.2025

Ενδιαφέρον!!!
Yanet Reyes
23.02.2025

Información completa, sencilla y clara.
Leandro Totti
21.02.2025

Lugar legal para ir c os filhos. Reservar com antecedência evita filas !
Bobby Hinkle
19.02.2025

Great views of East London
Maciej Pakulski
19.02.2025

There is an official paid entrance, but in order only to see Prime Meridian, I recommend Prime Meridian which can be accessed for free. There’s also a small gate near the park that some visitors use to access certain areas without paying.

 

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