Santiago Calatrava Valls (born 28 July 1951) is a Spanish-Swiss architect, structural engineer, sculptor and painter, particularly known for his bridges supported by single leaning pylons, and his railway stations, stadiums, and museums, whose sculptural forms often resemble living organisms.

[1] His best-known works include the Olympic Sports Complex of Athens, the Milwaukee Art Museum, the Turning Torso tower in Malmö, Sweden, the World Trade Center Transportation Hub in New York City, the Auditorio de Tenerife in Santa Cruz de Tenerife, the Margaret Hunt Hill Bridge in Dallas, Texas, and his largest project, the City of Arts and Sciences and Opera House in his birthplace, Valencia.

[3] Calatrava explained that he was particularly influenced by the work of the early 20th century Swiss engineer Robert Maillart (1872–1940), which taught him that, "with an adequate combination of force and mass, you can create emotion.

It is 128 metres (420 ft) long, with twin arches which lean at an angle of thirty degrees; a feature which quickly became the stylistic signature of Calatrava.

The upper portion of the bridge, composed of steel arches and cables, is light and airy, like a network of lace, anchored to the massive concrete supports and granite pillars below.

Its main feature is a single pylon 142 metres (466 ft) high, leaning to 58 degrees, the same angle as the Great Pyramid of Giza in Egypt.

In 1992, he completed one of his most picturesque and sculptural works, the Montjuïc Communications Tower in Barcelona (1989–92), a 136 m (446 ft)-high graceful concrete spire designed for the site of the 1992 Olympics.

The interior of the shopping mall is covered by a glass roof supported by columns like gigantic trees, a modern version of the Belle Epoque Les Halles market in Paris.

Similar to the galleria he designed in Toronto, but on a grander scale, the interior of the station features a forest of white columns like gigantic trees that support the glass roof, 238 by 78 metres (781 by 256 ft), which covers the eight tracks.

Built on a sloping site surrounded by vineyards, the 196-metre (643 ft) long building has an aluminum roof and a facade covered with laminated wood panels, alternating between convex and concave, with a roofline that ripples like a series of waves.

The building was originally conceived by the architect as a sculpture of "seven cubes stacked on a steel support creating a spiral structure resembling a twisting spinal column."

Calatrava also designed an enormous parabolic arch at the entrance and the Wall of Nations, a mobile sculpture of tubular steel which moves in a wavelike patterns.

On one side is the science museum, behind a line of leaning columns, and on the other is the newest structure, the massive shell of the opera house, described by Calatrava as a "monumental sculpture", which gives the impression of being continually in motion.

[15] Calatrava constructed a series of extraordinary bridges, the type of structure which originally brought him global attention, for cities around the world that wanted a symbol of modernity and daring.

Calatrava described the form in his own particular engineering vocabulary as "defined by a helicoidal movement, with an ovoid cross section, with two clearly materialized tangential lanes expressing an internal architectural volume."

The review in Architecture magazine, the journal of the American Institute of Architects, reported: "The building is full of handsome and even some very impressive spaces, but none of the singularly breathtaking ones that have made Calatrava, despite his price tag, so attractive to clients looking for marketing splash to go with their museum wing or train station.

The museum also includes a number of ecological features; water from the sea is used to regulate the temperature inside the building, and to refill the surrounding reflecting pools.

[23][24] The Guardian described it as "an other-worldly edifice that looks like a cross between a solar-powered dinosaur and a giant air conditioning unit", and declared "it must already rank as one of the world's most extraordinary buildings.

The new station connects the regional trains of the new PATH with the subway and other local transportation, and also has a large retail mall, replacing commercial space destroyed in the attack.

The underground station was originally designed so that its roof would open entirely in good weather, but this feature also had to be dropped due to its cost and space limitations.

[27][28] Michael Kimmelman, the architecture critic of the New York Times, praised the soaring upward view inside the Oculus, but condemned the building's cost, "scale, monotony of materials and color, preening formalism and disregard for the gritty urban fabric.

"[28] Daley wrote: "...in numerous interviews, other architects, academics and builders say that Mr. Calatrava is amassing an unusually long list of projects marred by cost overruns, delays and litigation.

In 2013 a Dutch councillor in Haarlemmermeer, near Amsterdam, urged his colleagues to take legal action because the three bridges the architect designed for the town cost twice the budgeted amount and then millions more in upkeep since they opened in 2004.

The glass tiles on the floor of his bridge in Bilbao became slippery in the rain, causing an increased number of claims for injuries and forcing the installation of a black anti-slip carpet on the decking, which blocked the view of the river through the walkway.

Calatrava's original entry pavilion was scaled back for security reasons[36] and the mechanism for opening the roof to the gallery below was eliminated because of budget and space restraints.

It's $2bn over budget, has suffered from construction problems and design compromises, it's seven years late and still incomplete, and its architect, Santiago Calatrava, has left a trail of lawsuits and angry clients around the world....But when I was standing on the marble floors in its enormous, gleaming central concourse two stories below street level, staring up at a clear blue sky between bone-white ribs vaulting 160ft over my head, I, like Jonah in the whale, repented – at least for the moment....We deserve grand expressions of our artistic and technological capabilities.

By the time we get to that future, whichever one it may be, the delays and the cost and the controversies will be forgotten, but we will be left with a luminous great hall in the heart of downtown New York.

"[41] In October 2023 the Greek government decided to shut down the Athens Olympic Stadium and Velodrome, which both have a roof built by Calatrava, due to stability issues posing a threat for attendees and workers.

In the journal of the American Institute of Architects, Christopher Hawthorne wrote about his design for Florida Polytechnic University, which he called "an example of Calatrava's architectural approach and creative sensibility distilled, for better and worse, to its essence.

[3] Calatrava defined his objective this way in 2016 in a book about his work: "My major interest is the introduction of a new formal vocabulary, composed of forms adapted to our time.