Although the site of Madrid has been occupied since prehistoric times, the first historical data that concerns the city dates from the middle of the ninth Century, when Mohammad I ordered the construction of a small palace (site occupied now by the Palacio Real). Around this palace there was built a small citadel (al-Mudaina). The palace was built overlooking the River Manzanares, which the Muslims called Mayrit meaning source of water (which in turn became Magerit, and then eventually Madrid). The citadel was conquered in 1085 by Alfonso VI in his advance towards Toledo. He reconsecrated the mosque as the church of the Virgin of Almudena (almudin, the garrison's granary), now the Catedral de la Almudena. In 1329 the Cortes first assembled in Madrid to advise Fernando IV. Jews and Moors continued to live in the city in their quarter, still known today as the "Moreria", until they were expelled. The Royal Palace of Madrid and the buildings and monuments of the Paseo del Prado (Salón del Prado and Alcalá Gate) deserve special mention. They were constructed in a sober Baroque international style, often mistaken for neoclassical, by the Bourbon kings. Plans for the construction of a new cathedral for Madrid dedicated to the Virgin of Almudena began in the 16th century, but the slow construction did not begin until 1879. Francisco de Cubas, the Marquis of Cubas, was the architect who designed and directed the construction in a Gothic revival style. Construction ceased completely during the Spanish Civil War. The project was abandoned until 1950, when Fernando Chueca Goitia adapted the plans of de Cubas to a neoclassical style exterior to match the grey and white façade of the Palacio Real, which stands directly opposite. and was not completed until 1993, when the cathedral was consecrated by Pope John Paul II. On Calle Princesa, in the heart of the district of Moncloa, lies el Ejército del Aire, the headquarters of the Spanish Air Force. A scaled-down replica of the famous Monastery San Lorenzo del Escorial which lies about 50 kilometers northeast of Madrid, el Ejército del Aire is a classic example of Fascist Neoclassicism in Madrid.

The financial district in downtown Madrid between the streets Raimundo Fernández Villaverde, Orense, General Perón and Paseo de la Castellana, its original conception (and its name) to the "Plan General de Ordenación Urbana de Madrid", approved in 1946. The purpose of this plan was to create a huge block of modern office buildings with metro and railway connections in the expansion area of northern Madrid, just in front of Real Madrid stadium (currently named the Santiago Bernabéu Stadium) and beside the brand new government complex of Nuevos Ministerios. A botanical garden, a library and an opera house were also included in the plans, but these were never built. Cuatro Torres Business Area is a business park that was completed in 2008. This block contains the tallest skyscrapers in Madrid and Spain (Torre Espacio, Torre de Cristal, Torre Sacyr Vallehermoso and Torre Caja Madrid). A new commercial and economic area with plenty of skylines is expected to be constructed during the next ten years according to the "Enlargement of Castellana Street Project":

Madrid Barajas International Airport Terminal 4, designed by Antonio Lamela and Richard Rogers (winning them the 2006 Stirling Prize), and TPS Engineers, (winning them the 2006 IStructE Award for Commercial Structures) was inaugurated on February 5, 2006. Terminal 4 is one of the world's largest terminal areas, with an area of 760,000 square meters (8,180,572 square feet) in two separate terminals. Consisting of a main building, T4 (470,000 square meter), and satellite building, T4S (290,000 square meter), which are separated by approximately 2.5 km. Hong Kong International Airport still holds the title for the world's largest single terminal building (Terminal 1) at 570,000 square meter. The new Terminal 4 is meant to give passengers a stress-free start to their journey. This is managed through careful use of illumination, available by glass panes instead of walls and numerous domes in the roof which allow natural light to pass through. With the new addition, Barajas is designed to handle 70 million passengers annually.

Environment

Madrid is full of green spaces and parkland; in central Madrid the largest park is Parque del Retiro, spreading out to the north-east of Atocha Railway station. The station is the core centre for high-speed AVE trains, with current lines to Valladolid (North-West), Barcelona (North-East) and Seville (South).

Madrid has many trees, both in parks and on the streets, with about 500,000. In 2005, the city had 300,000 and only Tokyo had more trees (100,000 more), but also had three times more population than Madrid.

Parque del Retiro, formerly the grounds of the palace built for Felipe IV, is Madrid's most popular park. Its large lake in the middle once staged mini naval sham battles to amuse royalty; these days the more tranquil pastime of pleasure boating is popular. Inspired by London's crystal palace, the palacio de cristal can be found at the south-eastern end of the park.

In the Retiro Park is also the Forest of the Departed (Spanish Bosque de los Ausentes), a memorial monument to commemorate the 191 victims of the 11 March 2004 Madrid attacks.

Atocha Railway Station is not only the city's first and most central station but also home to a distinctive indoor garden with 4,000 square meters of tropical plants. Atocha station has become a hothouse destination in itself for plant lovers, with more than 500 species of plant life and ponds with turtle and goldfish in, as well as shops and cafes. It's a nice place to visit on a cold or wet day with its even temperature of 24 degrees Celsius, or even on a scorching summer day as a retreat from the heat.

Casa de Campo is an enormous rural parkland to the west of the city, the largest of all Madrid's green areas. It is home to a fairground, the Madrid Zoo and an outdoor municipal pool, to enjoy a bird's eye view of the park and city take a cable car trip above the tree tops.

The Royal Botanic Garden or Real Jardin Botanico was an 18th century creation by Carlos III, it was used as a base for the plant species being collected across the globe. There is an important research facility that started life as a base to develop herbal remedies and to house the species collected from the new-world trips, today it is dedicated to maintaining Europe's ecosystem.

The theme park Faunia, is a natural history museum and zoo combined, aimed at being fun and educational for children. It comprises eight eco-systems from tropical rain forests to polar regions, and contains over 1,500 animals, some of which roam freely.