Carlo Simi (7 November 1924 – 26 November 2000) was an Italian architect, production designer and costume designer, who worked frequently with Sergio Leone and Sergio Corbucci, giving their spaghetti westerns a unique look.
 Most famous for his costume and set designs for "Once Upon a Time in the West" Simi also built the town of 'El Paso' in the Almería desert for Leone's second Western, "For a Few Dollars More".
 Built around a massive bank, with vistas of the Tabernas Desert visible between buildings, the set still exists, as a tourist attraction called "Mini Hollywood".
 Simi played the bank manager in that film: it was his only acting role.
Django ( , ) is a 1966 Spaghetti Western film directed and co-written by Sergio Corbucci, starring Franco Nero (in his breakthrough role) as the title character alongside Loredana Nusciak, José Bódalo, Ángel Álvarez and Eduardo Fajardo.
 The film follows a Union soldier-turned-drifter and his companion, a mixed-race prostitute, who become embroiled in a bitter, destructive feud between a Ku Klux Klan-esque gang of Confederate racists and a band of Mexican revolutionaries.
 Intended to capitalize on and rival the success of Sergio Leone's "A Fistful of Dollars", Corbucci's film is, like Leone's, considered to be a loose, unofficial adaptation of Akira Kurosawa's "Yojimbo".
Western Leone is a Western-style theme park in the province of Almeria, Andalusia (Spain).
 Located at the 378.9 km mark on the A-92 motorway, it is the smallest of three such theme parks in the Tabernas Desert; the other two are Mini Hollywood and Texas Hollywood.
 Western Leone was originally built to film Sergio Leone's "Once Upon a Time in the West" (1968); the large red house, around which much of the scenes in the film revolve, is maintained as an attraction, along with other buildings of a Western town.
 It has also been used to film other spaghetti westerns.
The Good, the Bad and the Ugly (Italian: "Il buono, il brutto, il cattivo" ,  "The good, the ugly, the bad" ) is a 1966 epic Spaghetti Western film directed by Sergio Leone and starring Clint Eastwood, Lee Van Cleef, and Eli Wallach in their respective title roles.
 Its screenplay was written by Age & Scarpelli, Luciano Vincenzoni and Leone (with additional screenplay material and dialogue provided by an uncredited Sergio Donati), based on a story by Vincenzoni and Leone.
 Director of photography Tonino Delli Colli was responsible for the film's sweeping widescreen cinematography, and Ennio Morricone composed the film's score including its main theme.
 It was an international co-production between Italy, Spain, West Germany and the United States.
Once Upon a Time in the West ( ) is a 1968 epic Spaghetti Western film co-written and directed by Sergio Leone.
 It stars Henry Fonda, cast against type, as the villain, Charles Bronson as his nemesis, Claudia Cardinale as a newly widowed homesteader, and Jason Robards as a bandit.
 The screenplay was written by Sergio Donati and Leone, from a story by Dario Argento, Bernardo Bertolucci and Leone.
 The widescreen cinematography was by Tonino Delli Colli, and the acclaimed film score was by Ennio Morricone.
El Húsar de la Muerte (Spanish: "The Hussar of the Death" ) is a 1925 Chilean silent film movie.
 "El Húsar de la Muerte" was directed and starred by Pedro Sienna.
Gonzalo Gavira (October 30, 1925 – January 9, 2005) was a Mexican movie sound technician.
 He formed part of the team that won an Oscar for the movie "The Exorcist" in 1973.
 Outside of Mexico he worked on more than 60 other films, including the disaster movie "The Towering Inferno" and western "El Topo", as well as Sergio Leone's "The Good, The Bad, And The Ugly".
 While working in the United States he always worked with an assistant named Ruben C. Bustamante, Mr. Gavira referred to him as invaluable.
 In 1975 he was awarded the Silver Ariel, which is the highest award that can be received from Mexican theatre.
 He died in 2005, reportedly from circulation problems.
 Along with working together with director Sergio Leone, Gonzalo Gavira worked with William Friedkin, Alejandro Jodorosky (The Holy Mountain) and the great Cantinflas, who on many occasions classified Mr. Gavira as a genius.
 Once upon meeting Lee Marvin, Gonzalo Gavira asked Mr. Marvin to autograph a twenty dollar bill.
 Lee Marvin refused, stating he would rather use that twenty to buy some drinks later, they became fast friends.
 Mr. Gonzalo Gavira worked on approximately 80% of all movie features made in Mexico.
 "Letters from Marusia" was nominated for Best Foreign Film at the 1976 Oscars and "Canoa" won Picture of the Year 1976 in Mexico City.
The Big Gundown (Italian: "La resa dei conti", lit.
 "The Settling of Scores") is a 1966 Italian Spaghetti Western film, co-written by long-time Sergio Leone collaborator Sergio Donati, directed by Sergio Sollima, and starring Lee Van Cleef and Tomas Milian.
 It was originally released by Columbia Pictures in the US as a double feature with "A Time for Killing".
Sergio Leone (] ; 3 January 1929 – 30 April 1989) was an Italian film director, producer and screenwriter, credited as the inventor of the "Spaghetti Western" genre.
Pedro Sienna (13 May 1893—20 March 1972) was a Chilean playwright, poet, journalist, art critic and theatre and movie actor who is also remembered as one of his country's pioneering directors in the early years of silent film.

Question: Which artist appeared in more movies, Pedro Sienna or Sergio Leone?
Answer: Pedro Sienna