Opposite the Casa Rosada on the Plaza de Mayo is the resplendent former Spanish town hall, the Cabildo, a fascinating old colonial building fronted by arches that once encircled the plaza, back during the May Revolution in 1810. While the building's construction originally began in 1610, it was almost immediately too small. Construction and changes were ongoing well into the 1800's, and the building was finally completed in 1894. It hasn't changed much since 1894, but has since become a museum.

The guards outside the building are members of the revered Regimiento de Patricios, which was formed in 1806, and the changing of the guard every hour is a popular attraction. They still wear their traditional uniforms they have donned for nearly 200 years.

The interior houses a small museum, which displays some interesting architectural relics, religious icons and watercolour paintings by Enrique Pellegrini, and it is all furnished in colonial period-pieces. The views from the Cabildo's windows are some of the best of the Plaza de Mayo. A crafts market is hosted on the back pation on Thursdays and Fridays, from 11am to 6pm.

Address: Calle Bolivar 65

Telephone: (011) 4342 6729

Opening times: Tuesday to Friday 11:30am-6pm, Saturday 2pm-6pm, Sunday 1pm-6pm.