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

View of the courtyard of the Taj Mahal. one of the most remarkable sights of Muslim architecture, UNESCO World Heritage Site, Agra, Uttar Pradesh, India, Asia

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

Meteora, ancient holy Monastery of Varlaam, UNESCO, Kalabaka, Greece

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

Chapel of the Langue of Aragon in St. John's Co-Cathedral, UNESCO, Valletta, Malta

Amer Fort (Amber Fort), Rajasthan, India

Ranakpur Jain temple (Chaturmukha Dharana Vihara), Ranakpur, Rajasthan, India

Al Khazneh (The Treasury), one of the most elaborate buildings of the ancient city of Petra, UNESCO World Heritage Site, Jordan, Middle East

Aerial of Sewell Mining Town, UNESCO World Heritage Site, Chile, South America

Remarkable building at the corner of Hans Broges Gade and Odensgade streets, Aarhus, Jutland Peninsula, Denmark, Europe

The remarkable city skyline of the Central Business District as viewed from the Marina Bay Sands Skypark in Singapore, Southeast Asia, Asia

Panoramic view of the Siegessaeule, Victory Column, towards east with the government district, the Reichstag building, Brandenburg Gate, TV Tower, skyscrapers in Potsdamer Platz, Potsdam Square, Mitte district, Berlin, Germany, Europe

Chalk cliffs, rock needle Aiguille and Porte dAval at the Falaise dAval in the evening light, Etretat, Alabaster Coast, La Cote dAlbatre, Normandy, France, Europe

The church of San Silvestro in the central Piazza Silvestri represents a remarkable example of the Romanesque architecture of the region, Umbria, Italy, Europe

The church of San Silvestro in the central Piazza Silvestri represents a remarkable example of the Romanesque architecture of the region, Umbria, Italy, Europe