The Palau Güell is a town mansion (translated literally a "palace") in Barcelona, Catalonia, Spain designed by the Catalan architect Antoni Gaudí for the Catalan industrial tycoon Eusebi Güell. It is part of the UNESCO World Heritage Site "Works of Antoni Gaudí". The home is centered on a main room for entertaining high society guests. Guests entered the home in horse drawn carriages through the front iron gates, which featured a parabolic arch and intricate patterns of forged iron-work resembling seaweed and in some parts a horsewhip. Animals could be taken down a ramp and kept in the livery stable in the basement where the servants resided, while the guests went up the stairs to the receiving room. The ornate walls and ceilings of the receiving room disguised small viewing windows high on the walls where the owners of the home could view their guests from the upper floor and get a 'sneak peak' before greeting them, in case they needed to adjust their attire accordingly.

The Casa Calvet is located in Calle Caspe, Barcelona and it is built in the typical Catalonian style. It comprises four stories, excluding the first floor and basement, and also contains a roof terrace. It is one of the many splendid architectural sites in Barcelona duly appreciated by locals and visitors alike. Antonio Gaudi was the mastermind behind the design of this building and was commissioned to this project by the son of Pedro Martir Calvet, the textile manufacturer. The choice was made based on the fact that Gaudi’s work had never failed to express modernity and proved successful with every design. Initially, the initiation of the project was delayed because of the rejection of Gaudi’s plans based on the fact that the desired structure exceeded the space allotted to Gaudi. Gaudi, who had no intentions of altering the design to the likes of the municipal architect, sent the plans back without modifying them and threatened that if the plans were not permitted to be implemented as they were, the design of the structure would be severely compromised. Hence, the Casa Calvet was constructed in a strict accordance with Gaudi’s ideas. An epic structure completely representing Antonio Gaudi’s style of work, the Casa Calvet adorns Barcelona like many other historic structures that one can find in the city.

Casa Batlló, is a building restored by Antoni Gaudí and Josep Maria Jujol, built in the year 1877 and remodelled in the years 1904–1906. The local name for the building is Casa dels ossos (House of Bones), and indeed it does have a visceral, skeletal organic quality. It was originally designed for a middle-class family and situated in a prosperous district of Barcelona. The building looks very remarkable — like everything Gaudí designed, only identifiable as Modernisme or Art Nouveau in the broadest sense. The ground floor, in particular, is rather astonishing with tracery, irregular oval windows and flowing sculpted stone work. It seems that the goal of the designer was to avoid straight lines completely. Much of the façade is decorated with a mosaic made of broken ceramic tiles (trencadís) that starts in shades of golden orange moving into greenish blues. The roof is arched and was likened to the back of a dragon or dinosaur.

La Pedrera, also known as the Casa Milà was constructed between 1905 and 1910 and was completed in 1912. The mastermind behind the designing of the structure was the prominent architect Antoni Gaudi, who was perhaps the most famous architect of his time, and his work is scattered in all of Barcelona today. Located in the Eixample district of the city, the Casa Milà was actually built for Roser Segimon and Pere Milà. In 1980, the building lost most of its glory as the paint wore off and the interior looked faded and worn out. After that, the Casa Milà was restored and renovated in order to revive its true glory, which can be seen today.

UNESCO has declared the building a World Heritage Site, because it is counted among the best works of Antoni Gaudi. The current owner of this property is Caixa Catalunya. The building has been constructed in such a way that all the residents of the flats can easily interact and communicate with each other, which was Gaudi’s idea again. He wanted everyone in the building to get to know each other and hence designed the building in this way.

The building features various exhibitions on its first floor where visitors can get a chance to appreciate the interior of the Casa Milà. The entrance for the second floor is charged and the rest of the floors are not accessible to visitors and general public.

The Temple Expiatori de la Sagrada Família (Templo Expiatorio de la Sagrada Familia; "Expiatory Church of the Holy Family"), often simply called the Sagrada Família, is a massive, privately-funded Roman Catholic church. Considered the master-work of renowned Catalan architect Antoni Gaudí (1852–1926), the project's vast scale and idiosyncratic design have made it one of Barcelona's top tourist attractions. The fact that the church is in the process of being built is as much part of the attraction as the building itself. Many tourists come especially to admire the sight of artists and construction workers as they contribute to completing Gaudí's masterpiece. The design of La Sagrada Família is replete with Christian symbolism. Its most striking aspect is its spindle-shaped towers. A total of eighteen tall towers are called for, representing in ascending order of height the Twelve Apostles, the four Evangelists, the Virgin Mary and, tallest of all, Jesus Christ.

Park Güell (Catalan: Parc Güell) is a garden complex with architectural elements situated on the hill of el Carmel in the Gràcia district of Barcelona, Catalonia, Spain. It was designed by the Catalan architect Antoni Gaudí and built in the years 1900 to 1914. It is part of the UNESCO World Heritage Site "Works of Antoni Gaudí". The focal point of the park is the main terrace, surrounded by a long bench in the form of a sea serpent. The curves of the serpent bench form a number of enclaves, creating a more social atmosphere. Gaudí incorporated many motifs of Catalan nationalism, and elements from religious mysticism and ancient poetry, into the Park. The large cross at the Park's high-point offers the most complete view of Barcelona and the bay. It is possible to view the main city in panorama, with the Sagrada Familia and the Montjuïc area visible at a distance.

Casa Vicens is a family residence designed by Antoni Gaudíand built for industrialist Manuel Vicens. It was Gaudí's first important work. It is added to the UNESCO World Heritage Site "Works of Antoni Gaudí" in 2005. It was built in the period 1883-1889. This early work exhibits several influences, most notably the Moorish (or Mudéjar) influence, particularly evident at the top. The house is constructed of undressed stone, rough red bricks, and colored ceramic tiles in checkerboard and floral patterns. The yellow, zinnia-flowered tile, designed by Gaudí, was manufactured by Vicens. The plan is asymmetrical with protruding gables and buttresses. Galleries project even farther at the top. Rooftop towers are reminiscent of Moorish architecture. Because the house is a private residence, its interior cannot be visited. Nevertheless, the house is generally open to "neighbours and citizens" on Saint Rita's Day, May 22.

Colegio Teresiano de Barcelona was designed and constructed by the prominent architect Antoni Gaudi for the Teresian order of nuns. The foundation of the building had already been laid by another architect and the first floor had also been built when Antoni Gaudi was designated the job of taking the building to completion by Reverend Enrique de Osso I Cervello.

The building was mainly constructed using brick and stone because the school ran on a rather limited budget. It has a simple gate made of iron and a few ceramic pieces for decoration. Because this building was one of Gaudi’s very first projects, it is very different from the style of work that he developed in the later stages of his career.

Gaudi’s work mostly draws inspiration from Gothic architecture, but this particular building has a few features that are different from the conventional Gothic style, including a distinct parabola shape of the building. It has been designed in a way that it allows natural light to pour in and illuminate the interior during the day.

One can compare and marvel at the Colegio Teresiano and the Palau Guell. Both buildings are very different from each other and yet, they were built by the same architect around the same period of time.

The Bellesguard is locally known as the La Casa Figueras. It has been built in the vicinity of the old Royal Palace. The construction theme is rather plain, and the structure has been constructed using bricks and stones. The benches placed at the front of the structure were designed by Domingo Sugranes, who was Gaudi’ assistant, and bear a striking resemblance to the building. The building itself is a masterpiece of the renowned architect Antoni Gaudi, and much unlike the rest of his gothic inspired work, this particular manor has a modernist look. Located at the Sarria Sant Gervasi district of Barcelona, the manor has been built on the site of the Martin of Aragon’s residence.
Gaudi, assisted by Domenec Sugranes I Gras and Joan Rubio contributed greatly in order to make the building reach its completion in 1917. During the project, unfortunately, Gaudi quit as the lead architect and Domenec took over the position. The building is situated halfway on the Collserola Mountain and hence has very picturesque surroundings.
Gaudí was assisted by Joan Rubio whilst Domènec Sugrañes i Gras, who created the various mosaics which adorn the house, took over as lead architect and completed the building in 1917 after Gaudi quit the project.