Montjuic Castle old military fortress on Montjuic Mountain overlooking the city, Barcelona, Catalonia, Spain, Europe

Patio de la Monteria courtyard in the Real Alcazar, UNESCO World Heritage Site, Plaza del Triunfo, Seville, Andalusia, Spain, Europe

Mosaic floor, ancient Roman ruins of Gamzigrad, UNESCO World Heritage Site, Serbia, Europe

The ruins of an old marketplace at the El Born Cultural and Memorial Centre archaeological site and museum, Barcelona, Catalonia, Spain, Europe

Challenge of Barletta Cellar, Barletta, Barletta-Andria-Trani, Apulia, Italy

Ancient Cathedral of Santa Maria Aprutiensis, Teramo, Abruzzo, Italy, Europe

Builders lay under floor insulation into a house extension in Ambleside, Cumbria, England, United Kingdom, Europe

Concrete being poured for a house extension floor, United Kingdom, Europe

Cropped close-up of swimming pool at Laguna Niguel

Reflection of a building on glass, Miami, Florida, USA

Plants in the desert, Djibouti, Djibuti, Africa, Afar Triangle

Plants in the desert, Djibouti, Djibuti, Africa, Afar Triangle

Plants in the desert, Djibouti, Djibuti, Africa, Afar Triangle