A cenotaph - which literally means Empty Tomb in Greek - is a tomb or monument erected to honour a person or group of persons whose remains are elsewhere.
Standing in Whitehall is probably the best-known cenotaph in the modern world. It was designed by Sir Edwin Lutyens and constructed from Portland stone. It is undecorated save for a carved wreath on each end and the words "The Glorious Dead".
The sides of the Cenotaph are not parallel, but if extended would meet at a point some 1 mile (1.6 km) above the ground. Similarly, the "horizontal" surfaces are in fact sections of a sphere whose centre would be 900 feet (270 m) below ground.
It is flanked on each side by various flags of the United Kingdom. The flags displayed since 2007 represent the Royal Navy, the British Army, the Royal Air Force, and the Merchant Navy.
Uniformed service personnel (excluding fire and ambulance personnel) always salute the Cenotaph as they pass. The Cenotaph is the site of the annual National Service of Remembrance held at 11.00am on Remembrance Sunday, the second Sunday in November.
The Armed Forces Memorial
This stunning memorial is the largest in the National Memorial Arboretum, a park of trees and memorials devoted to the concept of Remembrance.
It contains the names of 16,000 Service men and women killed on duty or by terrorist action since the end of the Second World War, engraved in stone around its walls.
Designed by Liam O'Connor, the Memorial is a magnificent piece of architecture in its own right. It embraces a peaceful setting with space for families and friends to remember their loved ones. The sculptural elements are by Ian Rank-Broadley.
The Memorial was dedicated in October 2007 by Her Majesty the Queen and each year since then, additional names have been added and dedicated.
Visit the National Memorial Arboretum website for more information.
There are estimated to be over 100,000 war memorials in the UK. The War Memorials Trust works for the protection and conservation of these but the responsibility for maintenance usually falls to the local authorities, as laid down in the War Memorials (Local Authorities' Powers) Act 1923.
The Commonwealth War Graves Commission's online database (www.cwgc.org) lists the 1.7 million men and women of the Commonwealth forces who died during the two world wars and the 23,000 cemeteries, memorials and other locations worldwide where they are commemorated.
The names of Service people who lost their lives since WWII are included on the Armed Forces Memorial (see above) and listed in the Roll of Honour, now available on the Veterans UK website, where you can search for a name and print a certificate.
There are a number of sites that allow you to create a "virtual" memorial or message of Remembrance. The Legion offers the option to plant a viritual poppy anywhere in the world.