Octagonal bell tower, Sanctuary of St. Michael the Archangel, Monte Sant'Angelo, UNESCO, Foggia, Apulia, Italy

Architectural detail of St. Peter's Basilica, featuring the iconic Vatican obelisk at its center, Vatican City, UNESCO World Heritage Site, papal enclave in Rome, Lazio, Italy, Europe

View of the New Fortress from Old Port Square, UNESCO World Heritage Site, Corfu, Ionian Sea, Greek Islands, Greece, Europe

Amer Fort (Amber Fort), Rajasthan, India

Temple of Isis, Temple of Philae, UNESCO World Heritage Site, Agilkia Island, Aswan, Egypt, North Africa, Africa

View of Aqueduct from Ottoman era, Dimos Kavalas, Eastern Macedonia and Thrace, Gulf of Thasos, Gulf of Kavala, Thracian Sea, Greece, Europe

Remarkable sandstone rock carved by erosion in the Ashar Valley, AlUla, Medina Province, Saudi Arabia

Noble Staircase, Bolsa Palace, UNESCO World Heritage Site, Porto, Norte, Portugal, Europe

Rock formations in the American Southwest

Foehn clouds over the Torres, Torres del Paine National Park, Patagonia, Chile, South America

Log cabins at the entrance to Torres del Paine National Park, Patagonia, Chile, South America

Signpost Cuernos and Chileno, Mirador Las Torres, Torres del Paine National Park, Patagonia, Chile, South America

Mountaineers at the Mirador de las Torres, Torres del Paine National Park, Patagonia, Chile, South America

View from the Mirador de las Torres, Torres del Paine National Park, Patagonia, Chile, South America

Aerial view of a single courtyard with an avenue of columnar cypresses (Cupressus sempervirens) and hills near Siena, Tuscany, Italy, Europe

Thor's Hammer, Bryce Amphitheatre, Bryce Canyon National Park, Utah, USA, North America

Ukraine Kiev Sophien cathedral 1054 seven of 13 domes of the cathedral golden domes and crosses shines in the sun blue sky 2004

Ukraine Kiev Sophien cathedral 1054 seven of 13 domes of the cathedral golden domes and crosses shines in the sun blue sky 2004

Australia, Sydney, View of Sydney Harbor from ferry.