Juan de Villanueva was one of the famous architects of Spanish Neoclassicism. He was born in Madrid on September 15, 1739. At the age of eleven, he joined the Royal Academy of Fine Arts of San Fernando. He traveled to Rome in 1758 to become a grant holder of the Academy to complete his studies. He was appointed as the architect of the prince by Charles III in 1777. From that point to death he almost worked exclusively for the royal house. He was appointed the Architect of the Royal Monastery of El Escorial in 1781 and Charles IV appointed him as the Major Architect. He constructs several buildings for the royal disposal. One of his masterpieces is the Prado museum. He was a creative architect and done most of his work in Madrid. He died on August 22,1811 and  was buried in San Sebastian church, Madrid.
Some works of Juan de Villanueva are:

Casita del Infante:

It is a historic building in San Lorenzo de El Escorial, Spain. It was constructed as a private home for the Infante Gabriel of Spain. It was built in the 18th century during the reign of CharlesIII of Spain. The Casita was built when it was popular for royal members to have a small"hideaway”. The most famous example is Marie Antoinette's Trianon. The Casita was built near the Renaissance monastery-palace of El Escorial during the years 1771 and 1773. The building was designed in Neoclassical style by Juan de Villanueva whose famous building is the Museo del Prado in Madrid.

Casita del Príncipe:

The  Casita del Príncipe (House of the Prince) is a build-in the eighteenth-century in El Escorial, Spain. It was designed by Juan de Villanueva for use of the heir to Spanish throne Prince of Asturian Charles,  and his wife Maria Luisa. It was constructed in the 1770s. The building is set in a formal garden. The garden is outlined by box privets in 18th-century style. It also has some bizarre conifers, such as Sequoiadendron giganteum, a species introduced in Europe in the 19th century. There is a Sala de Porcelana on the upper floor. This room has jasperware inscriptions in the neoclassical style. The plaques were made in Madrid in the 1790s by Retiro. It was declared Bien de Interés Cultural in 1992 under Spanish law.

Royal Botanical Garden: 

The garden was founded by King Ferdinand VI on October 17, 1755, and installed in Orchard of Migas Calientes, on the bank of Manzanares River. It consisted of more than 2,000 plants collected by José Query Martínez. In 1774, the garden was moved to Paseo del Prado by King Charles III orders.  The garden has a collection of 10,000 plants that are brought to Spain in 1794 by Alessandro Malaspina. The garden was abandoned in 1808 due to the Spanish war of independence, but Mariano de la Paz Graëlls y de la Aguera revived it in 1857 with a new greenhouse and refurbishment of the upper terrace. the garden has been dependent on CSIC (Spanish National Research Council) since 1939. In 1942, it was declared Artistic Garden. Now the garden is divided into seven outdoor sections and five greenhouses. It allows the cultivation of species that are not suitable to Madrid's Continental climate. Garden contains about 90,000 plants and flowers, and 1,500 trees.

Royal Academy of History: 

Real Academia de la Historia (Royal Academy of history) is an institution in Madrid which studies history "ancient, modern, civil, political, military, ecclesiastical, scientific, letters and arts. Moreover different branches of lifelike civilization and culture of Spanish people". The Academy came into being on 18 April 1738 by royal decree of Philip V of Spain. The Academy has an 18th-century building since 1836. The building was designed by the famous architect Juan de Villanueva. The academy building was initially occupied by Hieronymites. Earlier, it was the main institution in Spain for antiquaries, the Academy has considerable libraries and collections of antiquities, which aren’t allowed to be seen by the general public. The in-charge of these antiquities is a pre-historian Martín Almagro Gorbea. 

The items held include:

Some Spanish historians thought it as an obsolete misogynist the institution, which still considers kings and battles a matter of history. Though, the image has altered since Carmen Iglesias, the first female director, took over from Gonzalo Anes. By some authors, it is considered a "thoroughly undemocratic" institution "unrepresentative of Spanish historical profession" and a hotbed of historical revisionism.