Plaza 25 de Mayo is the heart of the city of Sucre, the actual true capital of Bolivia. Even today, almost every large and mid-sized city, and even most small towns and tiny villages, are built around a central plaza, in true Colonial fashion.
Typically, a city's central plaza is one of the most important points in the city, and this is especially true of Sucre, Bolivia. Here you'll find the Casa de la Libertad (Bolivia's Independence Hall, originally built in 1621 as part of a Jesuit convent) where you can view the country's Declaration of Independence, and paintings of Bolivia's presidents. This is where Bolivia was born as an independent nation on August 6, 1825 and Sucre is Bolivia's first city.
This young woman made a cute video of Sucre and sings as well:
Also surrounding Plaza 25 de Mayo are the Prefecture (state government building), the municipal (city government) building, and the city's the first cathedral "Catedral Metropolitana", built in 1559, and it's annex, the Chapel of the Virgin of Guadalupe, where you can see a painting of her, heavily encrusted in priceless jewels, along with other Colonial artwork.
Plaza 25 de Mayo is also encircled by shops, restaurants, travel agencies, and museums. The plaza itself is said to be one of the largest in Bolivia, although at the time of this writing (July 2011) the city was busy reducing its size to widen the surrounding streets. The plaza, as in any Bolivian city, is both a main meeting point and a place where people come to rest for a while among its beautifully maintained gardens and shady trees.
As the state and city government, and city council buildings are also here, the plaza is also often the stage for marches and protests, strikes, and the occasional violent confrontation. However, it is also used for many important events such as civic activities, concerts, and artistic venues.