The Citadel, Teotihuacan, Mexico State, Mexico

Avenue of the Dead and The Citadel at sunrise, aerial view, Teotihuacan, Mexico State, Mexico

Avenue of the Dead and The Citadel at sunrise, aerial view, Teotihuacan, Mexico State, Mexico

City looking north from the Acropolis, UNESCO World Heritage Site, Athens, Greece, Europe

Temple of Hercules ruins, Amman Citadel, Amman Governorate, Jordan, Middle East

Temple of Hercules ruins at sunset, Amman Citadel, Amman Governorate, Jordan, Middle East

The Catedral de Rabat at night in the ancient citadel of Victoria (Rabat) in the heart of Gozo, Malta, Mediterranean, Europe

The Acropolis of Lindos, Rhodes, Dodecanese Islands, Greek Islands, Greece, Europe

The Catedral de Rabat at night in the ancient citadel of Victoria (Rabat) in the heart of Gozo, Malta, Mediterranean, Europe

Temple of Hercules ruins, Amman Citadel, Amman Governorate, Jordan, Middle East

The Catedral de Rabat at night in the ancient citadel of Victoria (Rabat) in the heart of Gozo, Malta, Mediterranean, Europe

The Citadel, Teotihuacan, UNESCO World Heritage Site, north of Mexico City, Mexico, North America

View over the citadel of Gjirokaster, UNESCO World Heritage Site, Albania, Europe

The Citadel with the Buddhist stupa dating from 2nd century AD, from south west, Indus Valley civilization, Mohenjodaro, UNESCO World Heritage Site, Sind (Sindh), Pakistan, Asia

Great Bath of the Citadel from south, Indus Valley civilization, Mohenjodaro, UNESCO World Heritage Site, Sind (Sindh), Pakistan, Asia

Ritual bath in the citadel, Mohenjodaro, UNESCO World Heritage Site, Indus Valley civilisation, Pakistan, Asia

Children by ancient walls of Citadel, Ghazni, Afghanistan, Asia

Citadel columns, Amman, Jordan, Middle East

Algeria, Sahara, Tassili M'ajjer, Oasis Of Djanet, The Palm Grove Seen From The Ancient Citadel

Algeria, Sahara, Tassili M'ajjer, Oasis Of Djanet, The Ancient Fortified Citadel View From The Palm Grove

The ancient Alcazaba, 10th century citadel built by the Moors, Guadix, Andalucia, Spain, Europe

Old town, Salzburg, Austria

Clock tower on Schlossberg, castle hill, Graz, Austria

Ayaz Kala Fortress 2, photo taken from Ayaz Kala Fortress 1, Ayaz Kala, Khorezm, Uzbekistan

Buildings used as store rooms at the Citadel of Qaitbay, also known as Fort of Qaitbay, Alexandria, Egypt

Toprak Kala Fortress, Ellik Kala, Khorezm, Uzbekistan

The Erechtheion, at the Acropolis, Athens, Greece

Bam Fortress

Buildings of rock palace fortress on rock summit, Sigiriya, Central Province, Sri Lanka, Asia

Elephant ride in lake by rock palace, Sigiriya, Central Province, Sri Lanka, Asia

Fishing boats in the marina and the ancient Portuguese Citadel, Essaouira, Morocco

Fingers of the Statue of Hercules and the Jordanian Flag in front of the Archaeological Museum, Jebel al-Qala, Amman, Jordan

Greece, Ancient landmark citadel Acropolis in Athens, a UNESCO site, Europe

Scenic historic clay houses in the ancient UNESCO town of Ait Ben Haddou in Morocco

Drone view of the Perast coast with ancient houses and a tower. Montenegro.

Detail of the Roman Temple of Hercules, Jebel al-Qala, Amman, Jordan

Ruins of the Roman Temple of Hercules, Jebel al-Qala, Amman, Jordan

Ruins in the backlight, temple of Hercules, Amman Citadel, Amman, Jordan, Asia

Ruins, columns, temple of Hercules, Amman Citadel, Amman, Jordan, Asia

High angle view of ruins of buildings, Q'allaqasa, Pisaq, Peru

View of the fortified city of Obidos originated in an early Roman settlement, Oeste, Leiria District, Portugal, Europe

Middle East, Jordan, Karak Castle, the famous Crusader castle

Tourists walk in the alleys close to the old castle in the fortified town of Obidos, Oeste, District of Leiria, Portugal, Europe

Muslim woman wearing a black veil in front of the tower of the Arg-e-Karim Khani fortress, Shiraz, Iran

A tractor drives through a bustling market that flourishes below the old city walls in the town of Ghazni, Afghanistan.

Men on bikes ride past an ancient brick minaret toward the old walls and citadel of the town of Ghazni, Afghanistan, October 1, 2002. Made of brick decorated with Kufic and Naksh Script and floral motifs, the minaret dates back to the early 12th century and was built by Sultan Masud III of the Ghaznavid Dynasty, who ruled over an empire encompassing much of Afghanistan, Northern India, Persia and Central Asia. The minaret was once three times as tall as its current 70 feet, and is thought to have been part of a large mosque complex. Now an important truck stop on the road to Kandahar, Ghazni, located on the Lora River at the elevation of 2,225 meters, is the capital of Ghazni province with a population of 35,900, and is a market for sheep, wool, camel hair cloth, corn, and fruit.

The Erechtheion (or Temple of Athena Polias) with sunburst on the Acropolis of Athens, the ancient citadel located on a rocky outcrop overlooking the City of Athens at twilight, Athens, Greece

The Erechtheion (or Temple of Athena Polias) with sunburst on the Acropolis of Athens, the ancient citadel located on a rocky outcrop overlooking the City of Athens at twilight, Athens, Greece

Close-up view of the columns of The Parthenon against a blue, cloudy sky with a sunburst at twilight on the Acropolis of Athens, an ancient citadel located on a rocky outcrop above the City of Athens, Athens, Greece

Architecture at the Acropolis of Athens and a view of the city of Athens at sunset, Athens, Greece

David's Citadel And Wildflowers Growing On The Sloped Hillside, Jerusalem, Israel

David's Citadel, Old City Walls And Wildflowers Growing On The Sloped Hillside, Jerusalem, Israel

Parthenon, Acropolis of Athens; Athens, Greece

Parthenon, Acropolis of Athens illuminated at dusk; Athens, Greece

The sacred city of Machu Picchu sunlit and enveloped in low clouds; Cusco, Peru

View of the Acropolis of Athens from Lycabettus Hill, the center of Athens, Greece, Athens, Greece

The Islamic city of Shar e Gholgola at Bamiyan was destroyed by Genghis Khan in 1221. The ruins of the citadel are also known as the City of Sighs., Bamian Province, Afghanistan

View of the Bamiyan Valley from ruins of the citadel of Shar e Gholgola, Bamian Province, Afghanistan

PERU Cusco Department Machu Picchu Inca ruins terraces and Huayna Picchu. Cuzco Travel Tourism Holiday Vacation Explore Recreation Leisure Sightseeing Tourist Attraction Tour Destination Machu Picchu Machupicchu Huayna Wayna Peru Peruvian South Southern America Culture Cultural Tranquil Tranquility Sacred Valley Of The Inca Incas Inka Inkas Incan Hill Hillside Trail Mountain Mountainous Mountainside Overlooking Overlook Scenic Landscape View Vista Picturesque Dominant Dominating Prominent Andes Andean Ruins Remains Ancient Civilisation Civilization Peak High Tall Range Altitude Architecture Architectural Archaeology Archaeological UNESCO World Heritage Site Terraces Terraced Terracing Peaceful Landmark Vast Citadel Panorama Panoramic Lost City Remote Spectacular Magnificent Beautiful Secluded Seclusion Isolated Calendar American Cusco South America

PERU Cusco Department Machu Picchu Inca ruins terraces and Huayna Picchu. Cuzco Travel Tourism Holiday Vacation Explore Recreation Leisure Sightseeing Tourist Attraction Tour Destination Machu Picchu Machupicchu Huayna Wayna Peru Peruvian South Southern America Culture Cultural Tranquil Tranquility Sacred Valley Of The Inca Incas Inka Inkas Incan Hill Hillside Trail Mountain Mountainous Mountainside Overlooking Overlook Scenic Landscape View Vista Picturesque Dominant Dominating Prominent Andes Andean Ruins Remains Ancient Civilisation Civilization Peak High Tall Range Altitude Architecture Architectural Archaeology Archaeological UNESCO World Heritage Site Old Historic Peaceful Landmark Vast Citadel Panorama Panoramic Spiritual Ceremonial Lost City Remote Spectacular Magnificent Beautiful Secluded Seclusion Isolated Calendar American Cusco South America

PERU Cusco Department Machu Picchu Inca ruins and Huayna Picchu wall in foreground. Cuzco Travel Tourism Holiday Vacation Explore Recreation Leisure Sightseeing Tourist Attraction Tour Destination Machu Picchu Machupicchu Huayna Wayna Peru Peruvian South Southern America Culture Cultural Tranquil Tranquility Sacred Valley Of The Inca Incas Inka Inkas Incan Hill Hillside Trail Mountain Mountainous Mountainside Overlooking Overlook Scenic Landscape View Vista Picturesque Dominant Dominating Prominent Andes Andean Ruins Remains Ancient Civilisation Civilization Peak High Tall Range Altitude Architecture Architectural Archaeology Archaeological UNESCO World Heritage Site Old Historic Peaceful Landmark Vast Citadel Panorama Panoramic Spiritual Lost City Remote Spectacular Magnificent Beautiful Secluded Seclusion Isolated Wall Calendar American Cusco South America

PERU Cusco Department Machu Picchu Inca ruins terraces visitor sitting on terrace and Huayna Picchu. Cuzco Travel Tourism Holiday Vacation Explore Recreation Leisure Sightseeing Tourist Attraction Tour Destination Machu Picchu Machupicchu Huayna Wayna Peru Peruvian Culture Cultural Tranquil Tranquility Sacred Valley Of The Inca Incas Hill Hillside Trail Mountain Mountainous Mountainside Overlooking Overlook Scenic Landscape View Vista Picturesque Dominant Dominating Prominent Andes Andean Ruins Remains Ancient Civilisation Civilization Peak High Tall Range Altitude Architecture Architectural Archaeology Archaeological UNESCO Peaceful Landmark Vast Citadel Panorama Panoramic Spiritual Lost City Remote Spectacular Magnificent Beautiful Secluded Seclusion Isolated Terrace Terraces Woman Lady Person Sightseer Holidaymaker Alone Solitary Single One 1 Calendar American Cusco South America

Greece, Attica, Athens, The Parthenon at the Acropolis.

Greece, Attica, Athens, The Erechtheion, at the Acropolis.,

Egypt, Alexandria, Citadel of Qaitbay, also known as Fort of Qaitbay.

Greece, Attica, Athens, The Parthenon at the Acropolis

Greece, Attica, Athens, Close up of carved stone pediment of the Parthenon at the Acropolis.

Puerto Rico, Old San Juan, Morro Castle