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

Exploring a derelict stadium in Lithuania that hosted an unlikely Cold War matchup and an industrial relic in England.

Exploring two ornate buildings in Texas that were once at the heart of the Mexican Revolution and a top-secret facility outside Berlin, used by a ruthless dictator to escape justice.

Exploring a palatial ruin in Philadelphia built from the riches of an industrial golden age and a country palace in Poland, the scene of a honey-trap devised to ensnare Napoleon.

Exploring a concentration camp in the Czech Republic used for a publicity stunt to fool the world and a stark facility that once housed Oscar Wilde.

Exploring a nuclear-armed facility in Arkansas that served as America's last line of defence in the Cold War and an industrial relic in Wales that felt a young Winston Churchill's wrath.

Exploring derelict villas in Sicily that reveal the island's complicated history with the Mafia and an aristocratic mansion in Ireland embroiled in a bizarre terrorist plot.