England

Alnwick Poison Garden

Behind big black gates, the carefully curated garden contains about 100 legendary killers like Atropa belladonna (deadly nightshade), Strychnos nux-vomica (strychnine), and Conium maculatum (hemlock). Guides explain their deadly properties while keeping ne’er-do-wells and curious children away from the plants, warning them: “Do not touch any of the plants, don’t even smell them. There are plants here that can kill you.”

London Post Office Railway

The Post Office Railway, known as Mail Rail since 1987, is a driverless underground railway that was built to move mail between sorting offices.

The Outer Trial Bank

The Outer Trial Bank is a circular artificial island in the Wash, East Anglia, England. It is one of two islands constructed during the 1970s for a governmental water resources scheme.

The Kelvedon Hatch: Secret Nuclear Bunker

The Kelvedon Hatch Secret Nuclear Bunker at Kelvedon Hatch, in the Borough of Brentwood in the English county of Essex, is a large underground bunker maintained during the cold war as a potential regional government headquarters.

Excelsior Tunnel

In 1959 it was the centre of project Military Atomic Energy Authority operation orpheus investigating the possibility of masking the seismic signal given out by underground nuclear tests.

RAF Barnham

In the early l950s, RAF Barnham was selected for development as a dedicated storage and maintenance facility for nuclear weapons, in particular for Blue Danube, Britain's first nuclear bomb.

Thorpe Marsh Power Station

Thorpe Marsh Power Station was a 1 Gigawatt (GW) (1,000 MW) coal-fired power station near Doncaster in South Yorkshire, England.

Cane Hill Hospital

Cane Hill Hospital was a psychiatric hospital in Coulsdon in the London Borough of Croydon.

Hadrian’s Wall

Hadrian's Wall was a defensive fortification in Roman Britain, begun in AD 122 during the rule of emperor Hadrian. In addition to its military role, gates through the wall served as customs posts.

RAF Menwith Hill

Royal Air Force Menwith Hill or more simply RAF Menwith Hill is a Royal Air Force station in England which provides communications and intelligence support services to the United Kingdom and the United States of America. The site contains an extensive satellite ground station and is a communications intercept and missile warning site and has been described as the largest electronic monitoring station in the world.

Battersea Power Station

Battersea Power Station is a decommissioned coal-fired power station located on the south bank of the River Thames, in Battersea, an inner-city district of South West London.

Maunsell Forts

The Maunsell Forts were small fortified towers built in the Thames and Mersey estuaries during the Second World War to help defend the United Kingdom.

Stonehenge

One of the most famous sites in the world, Stonehenge is the remains of a ring of standing stones set within earthworks. It is in the middle of the most dense complex of Neolithic and Bronze Age monuments in England, including several hundred burial mounds.