Built in 1905 and originally called the Chardron Bookshop, the Livraria Lello & Irmão is a rare example of Neo-Gothic architecture in the city of Porto. Now a gorgeous bookstore, this building was one of the reasons why Porto was designated a World Heritage Site. The wonderful staircase running through the middle of the shop is an important feature, as is the stained-glass skylight and the ornate wooden ceiling. Visitors stop by this prized landmark to browse through their massive collection of books and enjoy the amazing ambiance.

This avenue is undoubtedly considered the heart of the city. To the north of the avenue, one can find the Praça do General Humberto Delgado, on which the Town Hall stands, and to the south, one will find the Praça da Liberdade and the statue of D.Pedro V on horseback. The Avenida dos Aliados was shortened at the start of the 20th Century to accommodate the Praça de Liberdade and it is famous for its Art Noveau architecture, which can be found on both sides of the avenue, as well as the gardens which can be found in the center.

Open to traffic since 1886, the Dom Luís I Bridge is a testament to ingenious European architecture. The bridge has a large arch with two roadways. Some of the techniques used on the steel work on the bridge were adopted some years before by Gustave Eiffel when he was responsible for another iron bridge in Oporto, the Dom Maria Pia. Thousands of cars cross the bridge daily, however you can take a relaxed walk over the bridge and enjoy the views of the Douro river.

Constructed in the 12th Century, the Sé do Porto (Oporto's Cathedral) was the center of the city during the entirety of the Middle Ages. It was within these walls that all the economic and political decisions were made. Apart from having a Roman foundation, the Sé do Porto has been altered many times throughout the centuries, even incorporating a baroque style, which is visible on the façade and the interior of the building. It is well worth visiting the Sé, especially on Sunday mornings, when one can hear the powerful organ reverberating throughout the building.

The magnificent Palácio da Bolsa is a splendorous triumph of Neopalladian design. At the end of the Portuguese Civil War, the site of the old monastery of San Francisco was granted to Porto's merchants for the construction of a grand palace that would serve as the seat of the Commercial Association. Joaquim da Costa Lima Júnior was commissioned to undertake the task and construction began in 1842. While much of the neoclassical facade was completed by 1850, the lavish interior decor would take another six decades to achieve. The grandest of the Palácio da Bolsa's many ornate rooms is the Arabian Hall, an elaborate chamber replete with intricate stucco and gilded embellishments pertaining to Moorish influences. The Pátio das Nações is no less astounding with its gleaming octagonal dome and the painted Coat of Arms of Portugal's 19th-century, commercial allies. Guided tours of the Palácio da Bolsa are also offered.

The Clérigos Church was considered as one of the biggest architectural projects in Porto during the 18th Century. A wonderful example of baroque architecture, it was built by Nicolau Nasoni, a renowned Italian architect and painter. Nasoni was Italian by birth, but he adopted Porto as his second home. His tomb can be found in the interior of the church. One of the main highlights of this church is the altarpiece of the chapel which was executed by Manuel dos Santos Porto and is made of polychrome marbles. A monumental tower, Torre dos Clerigos, which was built between 1754 and 1763, stands behind the church and is also a prominent landmark. It offers panoramic views of the surrounding area and is a favorite among tourists. While the entrance to the cathedral is free, visiting the tower requires a ticket.

One of the primary green spaces in Porto, Jardins do Palacio de Cristal is a Victorian-style garden which was designed in 1860. A German feat of architectural planning, this sprawling space offers stunning views of the Duoro river and the surrounding vistas. There is no price of admission and while you're there, be sure to check out the various areas which are segregated on the basis of themes, such as a rose garden, medicinal garden and an aromatic garden among others.

The Church of São Francisco (Porto) is located close to the Ribeira area. Featuring a striking façade, the revered landmark is visited by tourists and worshippers alike owing to its religious significance. The base structure is built in Gothic style, highlighted by the beautiful rose window above the gateway. The church was subject to a few changes, especially during the Baroque period (17th and 18th Centuries), and a survey of the portal enables visitors to observe the change in the original Gothic design. The interior has been decorated with all the magnificence of the 18th Century.

A unique way to travel around Porto and take in all the sights in a single sitting, Funicular dos Guindais is a must-do activity when you are in the city. This funicular connects the Ribeira and Batalha regions of the city and travels up a hill. Sitting in the semi-transparent box cars, you can enjoy breathtaking views of the city, and since this is an experience unique to Porto at such a nominal price, Funicular dos Guindais is well worth your time.

During the Middle Ages, this plaza was a very busy area where merchants, attracted to the Douro river's docks, gathered to do business. During the 18th Century, the English consul and architect John Whitehead and the governor João de Almada e Melo decided to rebuild the Ribeira Square. The large fountain, which exists to this day, dates from this period and on July 24, 2000 (Day of Saint John) a unique piece of sculpture representing the saint, made by Cutileiro, was added. Another noteworthy fountain here is the Cubo da Ribeira, created by José Rodrigues. Historically and architecturally significant, Ribeira Square is a must-visit for all!