The Leaning Tower, Piazza del Miracoli, Pisa, Tuscany, Italy

Photo of castle ruins in the countryside, Hadleigh Castle, Benfleet, near Southend-on-Sea, Essex, England, United Kingdom, Europe

Vertical garden by Patrick Blanc, Caixa Forum foundation, Madrid, Spain, Europe

Restoration of Notre Dame Cathedral, Paris, France

Columns surrounding the Forum, archaeological site of Pompeii, UNESCO World Heritage Site, province of Naples, Campania, Italy, Europe

Views of Base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

Pompeii, UNESCO World Heritage Site, Campania, Italy, Europe

Roman town of Herculaneum, UNESCO World Heritage Site, Campania, Italy, Europe

Aerial view of foundation structures for offshore wind farms at Cuxhaven Steel Construction, Cushaven, Lower Saxony, Germany

Tower of the collegiate church and parts of the historic house front on the Neckar, Tuebingen, Baden-Wuerttemberg, Germany, Europe

Futuristic architecture of Louis Vuitton Foundation building, Paris, France

Temple to Sobek, the crocodile god, and Harwer, the falcon diety at Kom Ombo, Egypt.

A view of the Rio-Antirio Bridge, the world's longest cable-stayed suspended deck bridge, from atop a ferry crossing the Gulf of Corinth near Patras, Greece on October 16, 2007.

Thailand, Sukhothai, Wat Mahathat, Buddha statue with many pillars at sunset, glowing sunlight on structure.

Inca Ingapirca, north of Cuenca, is Ecuador's greatest Inca archaeological site Sun Temple was main structure in the fortified Inca town, Highlands, Ecuador

Inca Ingapirca, north of Cuenca, is Ecuador's greatest Inca archaeological site Sun Temple was main structure in the fortified Inca town, Highlands, Ecuador

Inca Ingapirca, north of Cuenca, is Ecuador's greatest Inca archaeological site Sun Temple was main structure in the fortified Inca town, Highlands, Ecuador

Mixed race boy building geometric shape