Its cathedral, Catedral Metropolitana Nossa Senhora das Dores, dedicated to Our Lady of Sorrows, is the archiepiscopal see of the Roman Catholic Archdiocese of Teresina.

However, due to difficulties in communication and trade, the capital was transferred to an area next to the Parnaíba River, to the other cities and to the sea coast.

In the 19th century, it was initially called Vila Nova do Poty, but later the city was renamed Teresina, in honor of Empress Teresa Cristina, the wife of Emperor Pedro II of Brazil.

Sights include: Teresina is located on the east side of the Parnaíba river at the border with Maranhão state, at an altitude of about 72 meters.

Located in a transition zone between the northeast and the Amazon (Mid-North), Teresina is surrounded by mata dos cocais, savannas and cerradões where many carnaúba, babaçu, buriti palms, jatobás, ipês, and many other medium-sized trees can be seen.

In the region there are also remnants of Teresina Atlantic Forest, which makes the landscape shrub coverage very rich and dense.

From January to May, due to the rains, the weather is hot and wet (likely to occur when there is fog in the morning), while from June to August the climate gets dry with relatively milder nights; in September to December the weather becomes hotter and humid decreases, with the gradual return of rainy conditions from October.

This period is referred to as "Bro" by locals as the hottest months end with -bro in Portuguese: setembro, outubro, novembro, and dezembro.

A peculiar feature of the rains in the city are their speed and intensity, with strong winds, large force of water and very common lightning.

Air quality is considered good in Teresina, except in the driest period, when the relative humidity drops, and there are occurrences of fires.

Baptists constitute 2.62% of the population of the municipality, 0.86% Adventists, 0.12% are Presbyterians, 0.08% the other Protestant groups (Lutherans, Congregationals and Methodists) and 1.84% have no denomination.