A snowy stone bridge.
The Crystal Palace in Buen Retiro Park, Madrid.
Starry sky viewed from inside ruins.
A stone portal.
A stone cottage in the foothills of the Pyrenees, near Tarbes, France.
A stone cottage, part of Winterthur Museum and Gardens in Delaware.
Castle ruins by photographer S. Howse.
MinutePhysics explains how concrete sets and why it does not simply “dry out.” The water in wet concrete does not evaporate out. Instead, it causes chemical processes that change the compounds in the concrete itself, causing it to strengthen for months or even years after it is poured.
The Rock of Cashel in Cahir County, Tipperary, Ireland.