After Helsinki was proclaimed the capital of the Grand Duchy of Finland, it became obvious that the main city square, matching the new honorary status, was needed. It was tasked to the famous architect Carl Ludvig Engel. Arriving in the newly made capital at the beginning of the 19th century, the talented Finnish master did not stop at the construction of the central square. He also created most of the architectural ensemble along its perimeter.

The square was named Senate in honor of the monumental Senate building, which still houses members of the State Council. Unfortunately, the Council of State building is closed to tourists, as the current government of the country, led by the Prime Minister, has placed its offices there.

The other side of the square is occupied by the main building of the largest and oldest university in Finland, the University of Helsinki. Created also by Engel, the building of the university has many things in common with the former Senate building, like colors and the neoclassical style.

The educational institution stands close to the university library. This architectural monument is considered one of Engel's best creations.

Most importantly, the square houses the main shrine of the city and one of the most popular tourist attractions, St Nicholas' Church. Built for more than two decades, the majestic monument of sacred architecture is considered one of the most beautiful temples in Finland. It is a magnificent standard of the Byzantine architectural style, painted in sky blue and decorated with the largest collection of zinc sculptures in the world. The twelve holy apostles seem to be watching everything that happens in the capital's main square, as the cathedral stands right at its center. In front of the cathedral, there is a monument to the Russian Emperor Alexander II, reminiscent of the times when modern Finland was an autonomous part of the Russian Empire. The emperor wearing a guard officer uniform and four allegorical statues representing peace, labor, law, and enlightenment are made by two Finnish sculptors, Walter Runeberg and Johannes Takanen.