Exploring a once lavish palace in Iraq, the Sathorn Unique, an epic ghost tower in Thailand, and a former sports stadium in Georgia, USA

Exploring the remains of a pioneering industry town in Ohio, a once beautiful Croatian resort bombarded by enemy fire, and an otherworldly garden of Eden in Mexico.

The graffitied remains of a correctional facility in Atlanta, USA with a controversial and unexpected past, forgotten remnants of fraud and fusion on the Western border of Argentina and a mysterious ancient complex built by a devoted Khmer King in the jungles of Cambodia.

Exploring a ruined castle above a German village, a rural town in Idaho, a futuristic skyscraper in Johannesburg and a fantasy world outside of Buenos Aires.

Exploring a luxury resort in Argentina, a Greek palace above a Mexican city and a former hotel in Hawaii.

Exploring a crumbling dam hidden in the Welsh valleys, a quaint outpost on a paradise island, and a mastery of ancient engineering that brought life to the planes of Mexico.

Exploring a picturesque French castle, the ruins of a Kansas City hospital, an ancient Turkish city, and an island in Ireland that brought its inhabitants closer to God.

Exploring a complex in Georgia pointing into deep space that almost discovered a signal from aliens.

Exploring a royal retreat caught in a web of corruption, an engineering marvel hidden behind the Niagara Falls in Canada, and a subterranean treasure.

Explore Oradour-sur-Glane, a French town drenched in infamy, the victim of a notorious raid, Alcatraz, a facility famed for breakouts, subjected to a daring break-in, and Sealand, a micronation off the English coast, stormed by a band of mercenaries.

The Tunnels of Gibraltar were a Second World War espionage base, hidden in the Rock of Gibraltar, which lay undiscovered for decades. At Atlas-1 Test Site, are the remains of an ingenious US Airforce project that continues to keep people safe.

Exploring a series of vaults, hidden from view in Edinburgh, Scotland that tell a murky story of opportunity, crime and destitution.

Exploring the remains of an ingenious sky-high solution to a ground-based problem, Chiatura, once know as the Venice of the air

Exploring Agdam, a city in Azerbaijan raised to the ground in a conflict decided by a new weapon of war.

Exploring traces of a mass deception hidden at Ponte Dirillo in Italy, as well as a once lavish theatre in Ohio and an ancient city with a poisonous secret.

Explores a dense forest near the Czech capital of Prague that hides Houska Castle, an eerie keep that has been subject to long-standing rumours that it possesses supernatural powers.

Exploring Serbia, Fort Pike in Louisiana, and a mountainside refuge in Georgia that was revealed to the world by an act of God.

Exploring a grand structure in Hull that was reduced to rubble by Hitler's planes, Casa Albero in Italy, USS Hornet in California and the Sofia tunnels.

Exploring Air Studios, on the Island of Montserrat, that became a mecca for rock legends. Also Tskaltubo, in Georgia, built to host a fearsome dictator.

Exploring Haludovo Palace Hotel in Croatia, Wolf's Lair, a German military complex and Herouni Mirror Radio Telescope - a pioneering facility in Armenia.

Exploring a theme park in Buenos Aires built in a time of terror and dogged by controversy, and a jaw-dropping collection of castles in Turkey.

Exploring Old Byron Hot Springs in the Californian desert - a once glittering Hollywood hotspot, converted into a top-secret interrogation centre.

Exploring Yongma Land - a South Korean dreamland given a second life from the most unlikely of places.

Exploring Old Joliet Prison, a battered facility near Chicago that descended into open war, but then hosted the Blues Brothers!

Exploring Chateau Aubery on the island of Martinique, where a criminal kingpin wiped out the opposition.

Exploring Castel Volturno in Campana in Italy, Colorado and HMP Shepton Mallet in Somerset.

Exploring Camp Hero in Long Island, and a salt mine in Poland.

Exploring the Apollo Movie Theatre in Tbilisi, Georgia, an ornate shrine to Soviet propaganda.

Exploring a country estate in Ireland where family divisions reflected a national struggle and was caught in the crossfire.

Exploring Anchieta, a tropical island complex in Brazil and the scene of a dramatic uprising.

Exploring the ruined site of Troy, that helped decode one of the world's most enduring mysteries.

Exploring Seodaemun Prison, a facility in Seoul that helped spawn a legend known as South Korea's Joan of Arc.

We head to the Tunisian desert to explore a vast chain of ruins that once stood in the way of Allied Victory - until a band of rogue heroes uncovered their weakness.

Exploring an Oklahoman town so wealthy it inspired a Hollywood film.