Greek National Guard soldier (Evones) guarding the Tomb of the Unknown Soldier outside the Vouli Parliament building, Athens, Greece, Europe

Only section that remains of Iron Curtain in Czech Republic, 350m length of barbed wire fence and guard tower, Cizov, Podyji National Park, Brnensko Region, Czech Republic, Europe

Interior Ministry building, Revolution Square, Bucharest, Romania

The remains of a Guard Shack above the Johnson Canyon Railroad Tunnel. The railroad was abandoned in 1959 and is now owned by the Kaibab National Forest of Arizona. No property release needed.

Game guards patrolling on elephant back, Kaziranga National Park, Assam state, India, Asia

Guard of honor, Pakistan Rangers regiment, guards the tomb of National Poet Sir Muhammed Iqbal outside Badshahi Mosque, Lahore, Punjab, Pakistan, Asia

Guard of honor, Pakistan Rangers regiment, guards the tomb of National Poet Sir Muhammed Iqbal outside Badshahi Mosque, Lahore, Punjab, Pakistan, Asia

US servicemen, army, airforce, marines and navy provide security at The National World War II Memorial, Washington DC, USA

Traditional dressed guards in Fort George, Citadel Hill, a National Historic Site, Halifax, Nova Scotia, Canada, North America

Meerkat or suricate (Suricata suricatta) standing guard duty, Kgalagadi Transfrontier Park, encompassing the former Kalahari Gemsbok National Park, Northern Cape, South Africa, Africa

Guard at the Tomb of the Unknown Soldier, Arlington National Cemetery, Arlington, Virginia, United States of America, North America

Guard at the Tomb of the Unknown Soldier, Arlington National Cemetery, Arlington, Virginia, United States of America, North America

Park ranger with AK-47 Machine gun, Volcanos National Park, Rwanda

Park ranger with AK-47 Machine gun Volcanos National Park, Rwanda

A Mountain Gorilla (Gorilla beringei beringei) of the Muhoza group looks at a man in uniform, in Volcanoes National Park, Virunga mountain range, Rwanda.

Neuengamme concentration camp memorial site, SS main guard building with guard tower, right, prisoner block 1-4, centre, foundations of the detainee block, emerging thunderstorm, Hamburg, Hamburg, Hamburg, Germany, Europe

Museum of national history, Bishkek (Frunse), Kyrgyzstan

Soldier in front of National Capitol, Capitolio Nacional, Bolivar Square, Plaza de Bolivar, Bogota, Colombia, South America

Guard posted at the Monument to Genghis Khan beside the parliament buildings on Sukhbaatar Square, Ulaanbator, Mongolia

A US Border Patrol agent stands by the border fence that separates the United States and Mexico, Nogales, Arizona, USA

Observation tower of the GDR at the Grenzmuseum Schifflersgrund border museum at the former inner-German border, Sickenberg, Thuringia, Germany, Europe

Visitors on the Great Wall of China near Mutianyu in autumn, near Beijing, China, Asia

Watchtower, fence and visitors on the camp grounds, Dachau Concentration Camp, Dachau, near Munich, Bavaria, Germany, Europe

Watchtower with rainbow, Desert View Point, as seen from Navajo Point, Grand Canyon National Park, Arizona, USA, America

Two Cheetahs ( Acinonyx jubatus ) looking out from behind on a little hill - Masai Mara - Kenya, Africa

Watchtower and rainbow, Desert View Point, seen from Navajo Point, Grand Canyon National Park, Arizona, USA, United States of America

A National Guardsman wears a Nuclear radiation suit during training at an air base in South Dakota.

CHINA/Beijing/National Aquatic Center/17June2008:A soldier stands guard outside the National Aquatic Center at night. Designed by Australia's PTW Architects, its facade appearing as a cube of soap bubbles, it seats 17,000 people. The exterior is made from a high-tech lightweight translucent plastic that is also very energy efficient in saving an estimated 30% in power consumption by comparison to a traditional design. It houses 5 pools - one able to create it's own waves. It's outer surface looks like soap bubbles. It will host all swimming and diving events at the 2008 Olympics.

A plane refuels in the remote Western Antarctic.

Close Up Of Shoes Of Greek Presidential Guardsman, Athens, Attica, Greece

Greek Guardsman With Rifle From Waist Down, Athens, Attica, Greece

Legs Of Greek Presidential Guardsman With Rifle, Athens, Attica, Greece

Honour guard in gala uniform riding on horseback carrying the Yesun Hult Tsagaan Tug (The Nine White Banners) at the opening ceremony of the 2014 Naadam Mongolian National Festival celebration in the National Sports Stadium, Ulaanbaatar (Ulan Bator), Mongolia

Honour guard by Panteon Nacional de los Huroes (National Pantheon of the Heroes), Asuncion, Paraguay

BULGARIA Sofia Guard of honour outside the Presidency Building Honor Travel Tourism Holiday Vacation Explore Recreation Leisure Sightseeing Tourist Attraction Tour Sofia Capital City Bulgaria Bulgarian East Eastern Europe European Calendar Vivid Vibrant Stunning Striking National Patriotic Country Ceremony Ceremonial War Uniform Tunic Power Authority Military Army Warfare Strength Soldier Presidential Presidency President Guard of Honour Honor Sentry Protect Protection Defend Defence Guardsmen Guardsman Security Outside Outdoors External Exterior Serve Safeguard Gun Rifle Arms Bayonet Man Male Red White Glove Gloved Hand Braid Pattern Patterned Tassel Standing Stood Stand Upright Vertical Attention Resplendent Neat Tidy Smart Defense Eastern Europe

BULGARIA Sofia Guard of honour marching during changing of the guard outside the Presidency Building Honor Travel Tourism Holiday Vacation Explore Recreation Leisure Sightseeing Tourist Attraction Tour Sofia Capital City Bulgaria Bulgarian East Eastern Europe European Calendar Vivid Vibrant Stunning Dramatic Striking Summer Bright Sunny Sun History Historic Historical National Patriotic Country Ceremony Ceremonial War Uniform Cap Helmet Tunic Power Authority Military Army Warfare Strength Soldiers Presidential Presidency President Guard of Honour Honor Marching March Goose Step Goose-step Stepping Sentry Protect Protection Defend Defence Guardsmen Guardsman Security Outside Outdoors External Exterior Serve Safeguard Pavement Sidewalk Changing Formation Street Boots Gun Rifle Arms Bayonet Feather Men Man Male Defense Eastern Europe

USA, Washington DC, Arlington National Cemetery, Tomb of the Unknown Soldier, Changing of the Guard.

USA, Washington DC, Arlington National Cemetery, Tomb of the Unknown Soldier, Changing of the Guard.

USA, Washington DC, Arlington National Cemetery, Tomb of the Unknown Soldier, Changing of the Guard.

GHANA Mole National Park Armed wildlife guard with Savannah Elephants.

A white rhinoceros, Ceratotherium simum, in Masai Mara Rhino Sanctuary, escorted by anti-poaching guard. Masai Mara National Reserve, Kenya, Africa.

A white rhinoceros, Ceratotherium simum, in Masai Mara Rhino Sanctuary, escorted by anti-poaching guard. Masai Mara National Reserve, Kenya, Africa.