London may be the world centre of culture and commerce, but you will find the center of world time and space at The Royal Observatory in nearby Greenwich.

The observatory is home to Greenwich Mean Time and the Prime Meridian Line - two very significant features of science and geography in the world. Wherever you are in the planet, your distance going east or west is measured from the Prime Meridian. This line marks the center between the Earth’s eastern and western hemispheres - like the Equator does for the north and south.

The Observatory was established in 1675 by King Charles II , to help with the navigation of sea voyages. Navigation depends on knowing one’s exact position east and west. Eventually, the standards established at Greenwich became recognized as the world standard, still in use today.

Starting in 1884, The Greenwhich Meridian has been established as Longitude Zero Degrees  - making it the center of world-time or the starting point for each new day, year or century. UNESCO has recognized the historic significance of this location by declaring it a World Heritage Site.

The Royal Observatory is now part of England’s National Maritime Museum. It houses galleries and artifacts on time, space and astronomy. It is also home to London’s one and only public camera obscura.

Another fascinating artifact you’ll want to see when you visit Greenwich is the Red Time Ball. For decades, this ball has slid up and down a pole on top of Flamsteed House in order to mark the time. Flamsteed was the first Royal Astronomer. When the weather is good, the red ball is visible for miles around. It has been used to synchronize clocks and provide amusement for millions.

Now if you are interested in setting your watch accurately, you will want to check out a more modern timepiece that is housed at the Royal Observatory, embedded in one wall: a digital read-out kept accurate by connection to 200 atomic clocks around the world. This is as precise and correct a time as you can get.

Among other interesting artifacts on display are many of the observatory’s 360 telescopes, dating from the mid-17th century. Everything from fashion accessories to gun-sighting telescopes used in WWI are housed here.

Naturally, while here, you will want to stand on both sides of the Prime Meridian and take a photo. There aren’t many opportunities, after all, to be in two times at the same place.

Greenwich and the Royal Observatory are easily reached from London via the Underground subway or ‘the tube’ as it is known locally. Exit at North Greenwich.

Here are the tours and destination London.

• Leeds Castle Private Viewing, Canterbury and Greenwich Day Trip from London

Leave the hurly-burly of London for the day and tour the highlights of Kent. You’ll have an exclusive private viewing of Leeds Castle, dubbed the loveliest castle in the world. You’ll also tour the famous cathedral city of Canterbury, have lunch overlooking the famous White Cliffs of Dover, visit historic Greenwich, then cruise back to London in the early evening.

• Edinburgh Rail Day Trip from London

Who would believe traveling from London to Edinburgh on a one-day rail excursion was possible! Come along and enjoy a panoramic tour of Edinburgh onboard an open top bus - walk down The Royal Mile, and visit the famous Edinburgh Castle.