Top 20 Most Famous Unfinished Buildings

This ancient Roman temple in Rome, Italy, is considered one of the greatest architectural achievements of all time. Built in 126 AD, it was designed by architects Marcus Agrippa and Apollodorus of Damascus. The Pantheon stands at an impressive 43 meters (141 feet) high and has a large dome with an oculus, allowing natural light to illuminate the interior. The temple is famous for its engineering feats, including its concrete dome, which was considered impossible at the time of its construction. Completed in just five years, the Pantheon's construction required significant advancements in architectural techniques.

This former Orthodox patriarchal basilica in Istanbul, Turkey, was built between 532 and 537 AD under the reign of Emperor Justinian I. The iconic building's design is a masterpiece of Byzantine architecture, featuring six massive marble columns and a large central dome that can accommodate up to 15,000 worshippers. Hagia Sophia stands at an impressive 56 meters (184 feet) tall and has been recognized as one of the greatest architectural achievements in history. Its construction required the use of advanced engineering techniques and innovative designs for its vast interior spaces.

This stunning white marble mausoleum in Agra, India, was built between 1632 and 1653 by Mughal Emperor Shah Jahan as a tribute to his beloved wife, Mumtaz Mahal. The Taj Mahal is renowned for its symmetrical and perfectly proportioned design, with intricate marble work and ornate inlays of precious stones. The mausoleum stands at an impressive 73 meters (240 feet) tall and features a large reflecting pool surrounded by beautiful gardens. Its construction required the labor of thousands of skilled craftsmen and took over 22 years to complete.

This iconic ancient Greek temple in Athens, Greece, was built between 447 and 432 BC under the supervision of architects Ictinus and Callicrates. The Parthenon's design is characterized by its Doric columns, pediments, and a beautiful frieze that tells the story of Athena's victory over Poseidon. The temple stands at an impressive 13 meters (43 feet) tall and has been recognized as one of the greatest surviving examples of ancient Greek architecture. Its construction required significant advances in engineering techniques and artistic expression.

This iconic museum in Bilbao, Spain, was designed by Frank Gehry and built between 1993 and 1997. The building's flowing, curvaceous design is made from over 40,000 tons of stainless steel and features a stunning atrium with natural light pouring in through the glass roof. The Guggenheim Museum stands at an impressive 45 meters (148 feet) tall and has become a symbol of Bilbao's rebirth after industrial decline. Its construction required significant investments and took over four years to complete.

This iconic Art Deco skyscraper in New York City, USA, was designed by architect William Van Alen and built between 1928 and 1930. The building stands at an impressive 319 meters (1,047 feet) tall with a distinctive spire that was initially intended to be the tallest building in the world. The Chrysler Building features a unique metallic facade made from aluminum and glass, as well as ornate decorations inspired by ancient Egyptian and Native American art. Its construction required significant investments and technological advancements.

This iconic skyscraper in New York City, USA, was designed by architects Shreve, Lamb & Harmon Associates and built between 1930 and 1931. The building stands at an impressive 381 meters (1,250 feet) tall with a distinctive Art Deco design featuring steel spires and ornate decorations. The Empire State Building held the record for the world's tallest building until 1972 and has become an iconic symbol of New York City. Its construction required significant advances in engineering techniques and materials.

This undersea railway tunnel connecting England and France was built between 1994 and 1996 by a consortium of French and British companies. The tunnel stretches for approximately 50 kilometers (31 miles) beneath the English Channel, featuring two parallel tracks that support high-speed trains traveling up to 320 kilometers per hour. The construction of the Channel Tunnel required significant advances in engineering techniques, including the use of advanced drilling technologies and waterproofing systems.

This iconic bridge spanning the River Thames in London, UK, was built in multiple stages between 1209 and 1831. The current bridge is a Victorian-era structure featuring a distinctive Gothic-inspired design with a large central arch. The original Roman bridge that once stood on this site has been largely destroyed over the centuries, but its legacy continues to shape the development of modern London Bridge. Its construction required significant advances in engineering techniques, including the use of stone and iron.

This stunning white marble temple in New Delhi, India, was built between 1978 and 1986 by Iranian architect Fariborz Sahba. The temple's unique design features 27 marble cladded pavilions arranged around a central pool of water, forming a striking lotus flower shape inspired by the Hindu scripture of the same name. The Lotus Temple has become a symbol of peace and harmony in New Delhi and attracts millions of visitors each year. Its construction required significant advances in architectural techniques, including the use of advanced concrete and steelwork.

This iconic performing arts center in Sydney, Australia, was designed by Danish architect Jørn Utzon and built between 1959 and 1973. The building's distinctive sail-like design features six interlocking arches that support a large central dome made from precast concrete sections. The Sydney Opera House has become an iconic symbol of Australian culture and architecture, with its construction requiring significant advances in engineering techniques and materials.

This stunning Gothic cathedral in Lincoln, UK, was built between 1192 and 1311 under the supervision of architect William de St Francis. The cathedral's impressive design features a large central nave supported by six columns, a striking vaulted ceiling, and a distinctive tower that rises to an impressive 525 feet (160 meters) tall. Its construction required significant advances in engineering techniques, including the use of advanced stone carving and stonework.

This stunning Islamic palace complex in Granada, Spain, was built between 1238 and 1492 under the supervision of architects Muhammad ben al-Ahmar. The Alhambra's intricate design features a unique blend of Moorish and Gothic architectural styles, with intricate stone carvings and ornate decorations throughout its walls and courtyards. The palace complex has become a symbol of Spanish culture and architecture, with its construction requiring significant advances in engineering techniques.

This iconic steel suspension bridge in Sydney, Australia, was designed by British engineer John Bradfield and built between 1923 and 1932. The bridge stands at an impressive 494 meters (1,621 feet) long and features a distinctive Art Deco design with a large central pier that supports the roadway. Its construction required significant advances in engineering techniques, including the use of advanced steelwork and electrical systems.

This iconic suspension bridge in San Francisco, USA, was designed by engineer Joseph Strauss and built between 1933 and 1937. The bridge stands at an impressive 1.7 kilometers (1.06 miles) long and features a distinctive Art Deco design with a large central tower that supports the roadway. Its construction required significant advances in engineering techniques, including the use of advanced steelwork and hydraulic systems.

This iconic clock tower in London, UK, was designed by architect Charles Barry and built between 1843 and 1859 as part of the Houses of Parliament. The clock tower stands at an impressive 96 meters (315 feet) tall and features a distinctive Gothic-inspired design with four large bells that chime on the hour. Its construction required significant advances in engineering techniques, including the use of advanced clockwork mechanisms.

This iconic steel monument in Brussels, Belgium, was designed by architect André Waterkeyn and built between 1958 and 1960 for the World's Fair. The atomium features a unique design inspired by atomic structure, with nine interconnected spheres that represent different elements of the periodic table. Its construction required significant advances in engineering techniques, including the use of advanced steelwork and welding.

This iconic communications tower in Toronto, Canada, was designed by architect John Andrews and built between 1973 and 1976. The tower stands at an impressive 553 meters (1,815 feet) tall and features a distinctive postmodern design with a large central viewing platform that offers breathtaking views of the city.

This iconic skyscraper in Dubai, UAE, was designed by American architect Skidmore, Owings & Merrill and built between 2004 and 2010. The tower stands at an impressive 828 meters (2,722 feet) tall and features a distinctive modern design with a large central core that supports the building's glacial elevators. Its construction required significant advances in engineering techniques, including the use of advanced concrete and steelwork.

This iconic iron lattice tower in Paris, France, was designed by engineer Gustave Eiffel and built between 1887 and 1889 for the World's Fair. The tower stands at an impressive 324 meters (1,063 feet) tall and features a distinctive Art Nouveau design with four large pillars that support the central core. Its construction required significant advances in engineering techniques, including the use of advanced ironworking and lattice structures.