Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet Initiative has ...

Famous landmarks draw millions of visitors each year, but most people only see what’s on the surface. Behind the grand facades and well-photographed exteriors lie hidden rooms, secret passages, and ...

In a dramatic photograph from September 1921, a prisoner lies sprawled against a wall in Kilmainham Gaol. His eyes are closed, his mouth open. Four hard-bitten British soldiers crouch around the body, ...