Spain, Castile and Leon, Avila, City walls that were built from 1090 onwards and are among the best-preserved and most complete in Europe, looking along the northern section of the walls.

Spain, Castile and Leon, Avila, City walls with the circular Avila Cathedral built into the walls that were built from 1090 onwards and are among the best-preserved and most complete in Europe.

France, Indre-et-Loire, Chenonceaux, Formal gardens with pink flowerbeds surrounding circular fountains.

Austria, Tyrol, Innsbruck, Dom zu St Jakob or Cathedral of St James, dome interior and ceiling with frescoes by Cosmas Damian Asam.

Austria, Tyrol, Innsbruck, Dom zu St Jakob or Cathedral of St James, dome interior with frescoes by Cosmas Damian Asam.

Spain, Castile and Leon, Segovia, Traffic signs with the Aqueduct of Segovia, a Roman aqueduct with 167 arches built around the first century AD to channel water from springs in the mountains 17 kilom...

Food, Cooked, Pizza, Frozen pepperoni and jalapeno pizza on metal tray ready to be cooked.

Food, Cooked, Pizza, Frozen pepperoni and jalapeno pizza on metal tray ready to be cooked.

Food, Cooked, Pizza, Frozen pepperoni and jalapeno pizza on metal tray ready to be cooked.

Afghanistan, General, Kirghiz building circular frame for yurt.

Vietnam, Food and Drink, Circular shallow dishes of drying deep pink and yellow sweets.

Ireland, County Sligo, Carney, Bubbles on colourful background produced by mixing vegetable cooking oil with water and photographing the results with a close up lens.