Greenwich is home to Greenwich Mean Time and is located at 0.00ºE. This old London borough winds along the southern bank of the River Thames in the East of London. As well as being the self-proclaimed home of time, Maritime Greenwich is a World Heritage site and the borough is filled with royal history.

The prime experience in Greenwich is to straddle the line where the Eastern and Western hemispheres meet at Longitude Zero, which is 0.00ºE or 0.00ºW dependent on your perspective. From the Thames, visitors can walk through Greenwich Park to the Royal Observatory and the Planetarium, where the historic line is located.

The UNESCO Maritime Greenwich area is home to a handful of attractions, including the Royal Navy College, National Maritime Museum, and Queen's House. Entry to all these attractions is free. The Cutty Sark is the British Empire's most famous vessel and spent close to century delivering tea from the colonies to London. Fully restored, the 65-meter wooden and gold ship is a major London attraction.

Cruising along the River Thames is the iconic way for visitors to reach Greenwich from Central London. This public boat service passes many of Greenwich's famous attractions along the river. North Greenwich is the only London Underground station but is over 45 minutes walk to the World Heritage site. A quicker way to travel to Greenwich is an overland train from London Bridge, or the Docklands Light Railway (DLR) to Greenwich, Cutty Sark, and Woolwich stations.

The Greenwich Meridian was established by telescope over the 18th and 19th centuries, before being globally agreed at a meeting in Washington in 1884. However, gravitational changes have caused the line to shift 100 metres to the east. This causes some confusion when visitors stand on Longitude Zero while simultaneously checking GPS coordinates on their smartphone.