Fortaleza de Santa Teresa Fortaleza de Santa Teresa , or Fortaleza Santa Tereza is a military fortification located south of Chuy and northeast of Montevideo on Route 9 , in the Rocha Department of eastern Uruguay . It lies about from the coast at Playa la Moza , almost halfway between Angostura ( to the south ) and La Coronilla ( to the north ) , north of Punta del Diablo and roughly northeast of the northeast bank of the Laguna Negra . It lies within the Santa Teresa National Park . It was erected from October 1762 by the Portuguese , having abandoned the attempt at building a fort in Maldonado and leaving the Fuerte San Miguel . Topography . The region is characterized by vast expanses of dunes on the coast , as well as a series of wetlands located west and north . The fort was strategically located on a rocky outcrop at 58 m above sea level along the Camino de la Angostura , the only way through the marshes to the sea . Description . It has the shape of an irregular pentagon , and five angles are finished in projecting bastions . There are five checkpoints for each angle of the pentagon , elegantly constructed in the form of carved stone pulpit . The perimeter of the fortress measures 652 meters and it occupies one hectare in area . The walls are massive , built with huge granite masonry , strictly equal in size and perfectly carved . The outer wall is about four feet thick at the base and about two meters , the interior , filling the space between one and another . A solid embankment in some places is up to 7 m wide . The height of the outside walls in some places reaches to 11 . 5 m . " “ La puerta principal ” " It is built of solid wood arched at the top and looks to the west . " “ La Puerta oculta de socorro ” . " Looks south , and is of smaller proportions than “ la Puerta Principal ” . " “ El Túnel de la Trinchera ” " corresponds to what is now identified as a deep trench with walls of smaller stones located in front of the fortress in an east - west direction . " “ El Túnel del Arca ” . " is supposed to be hidden underground under the Fort . According to oral tradition , it consists of three or more rooms connected by walkways and a large tunnel that goes to the East . The output would be found somewhere near the Atlantic Ocean about 2000 m away . The popular belief here is that a secret artifact is hidden underground called the Arca secreta del Padre Lucas . Inside the fortress it lodged a maximum of about 300 men . The interior construction , also of stone masonry , preserved in perfect condition from the colonial era , have been restored with care and replacement roofs added . These buildings are : the flag room and guardia on the sides of the front door , the main , which was formerly the chapel , two large blocks , and the " polvorín " , built with huge blocks of granite and the cells . The cemetery is located a short distance from the west wall , and used from the second half of the eighteenth century to beyond the extinction of the fortress as such , since it continued to be in use in the neighborhood . Enlisted men lie there , the strong Spanish garrison in the area , Spanish , slaves , Indians and Portuguese alike . Of major note are Agustín Lipopisi and Félix Sayobí , two Guaraní chiefs and missionaries of San Carlos y Chorpus , Cecilia Maroñas , daughter of the Spaniard Francisco Maroñas and Portuguese María Espíndola , one of the sons of Commander Alagón who attacked by a cougar in Potrerillo , and many others . Like the fort , the small enclosure was built by the former Jesuit Lucas Marton , with convicts , and Guaraní Indians . It was designated as the first sector to be restored . Although the condition was not good , it maintained its original layout and stones , albeit collapsed , were in place . The small crosses are the original stone , not the large stone cross though , which was carved by the master mason Juan Buzzalini who served in the whole process of restoration of the fort . History . The current Fortaleza de Santa Teresa was built by the Spanish crown , though its foundation and name are due to Portugal . In the brief period from 1762 to October 1775 , they built three forts . The signing of the Treaty of El Pardo ( 1761 ) in practice nullified the Treaty of Madrid ( 1750 ) . Governor and Captain General of the Captaincy of Rio de Janeiro , Gomes Freire de Andrade , anticipated its consequences for the southern region and ordered troops to the region . Bringing a little more than a thousand men , the Portuguese strategy was to quickly build a fortified defensive line , south of Fuerte San Miguel to stop the Spanish invasion in progress . After the conquest of Colonia del Sacramento in October 1762 by the governor of Buenos Aires , Pedro de Cevallos , the fort began construction with about 400 soldiers and armed with a few pieces of small arms . The site chosen was the strategical pass of Angostura near the Castillos Grande . The fort , designed by Gómez de Mello , consisted of a trench dug in the slope of a hill site , known as Chico Castillo . The timber was moved from the area of Fuerte San Miguel , about 30 km distant , a daunting task for the time , because they had to ford countless streams and swamps . On October 6 , 1762 , a cornerstone was laid at the foot of the foundation and the fort was given the name in honor of Saint Teresa . However , construction was halted due to the war . However , in the war between Spain and Portugal , the Spanish general Pedro de Cevallos ordered the construction of another fort , directed against Portuguese Brazil , designed by Francisco Rodríguez Cardozo . Materials were used from the building that had been started . Ceballos then continued on his way to São Pedro do Rio Grande , in the same month taking Fuerte San Miguel , near the Arroyo Chuí . The Treaty of San Ildefonso ( 1777 ) confirmed the Spanish possession of the Fortaleza de Santa Teresa and the Fuerte San Miguel . A third fortification was built between 1765 – 1775 , designed by engineer Bartolomé Howel and built by ex - Jesuit Lucas Marton and Guaraní Indians . With the imminence of a British invasion in 1775 , Bernardo Lecocq worked to strengthen the structure of the fort as he did with the Fuerte San Miguel . Other repairs were made in 1797 . In 1776 , a year after completing the construction of the Fortaleza de Santa Teresa , Portugal returned to threaten the Spanish in these parts of Latin America . Governor Juan José de Vértiz y Salcedo moved from Buenos Aires to organize the defense , pending General Pedro de Cevallos and his army to carry out a counterattack . Upon arrival , they received news of the signing of the peace treaty of San Ildefonso , suspending all activities . Cevallos nevertheless was promoted as Captain General and became first viceroy of Río de la Plata . From that time the fortress was held until 1828 , with the emergence of the Eastern Republic of Uruguay , becoming state property . By the Treaty of May 15 , 1852 , which established the border demarcation at the mouth of the Chui Stream and the San Luis River , the two forts ( San Miguel and Santa Teresa ) remained in Uruguay . Once Uruguay was established , the state , for nearly a century , had no resources to preserve historical monuments . Thus began the decline of the Fortaleza de Santa Teresa . Nevertheless , it fulfilled its role as a watchtower on the border during the presidencies of Fructuoso Rivera and Manuel Oribe , between 1830 and 1843 . During the so - called Guerra Grande in the mid - nineteenth century , it was occupied by Manuel Oribe , but afterwards the structure was abandoned . In 1895 it was reoccupied as a prison . However , the total abandonment came about and it served to shelter cattle and bats , the latter inspired the former president Dr . Baltasar Brum to write a literary composition based on an Indian legend of the place . In 1921 , under Brum , the historian and archaeologist Horacio Arredondo conceived and proposed to restore it and preserve the Fort of San Miguel and the Fortaleza del Cerro in Montevideo . In 1928 his plan was put into practice and the forts were restored . Since the 1940s , it has contained a museum and been a tourist site ; one of the few bastions of the colonial era in America which still survives . Folklore and legends . The following legend was written by Baltasar Brum in 1930 based on an indigenous legend of the place . It recounts the formation of the hills with an emphasis on the origin of the Cerro Verde ( the complete original version is on La Fortaleza de Santa Teresa ) . " The Heart of stone siren " According to the legend : " the spirits of the elements that inhabited the seas and land , after the triumph of Christianity there , migrated to our continent in search of tranquility , but they were discovered and lost their freedom . Lovers of beauty and peace , they refused to fight against the human gods , and therefore , during a large gathering , decided to mutate in forms reminiscent of their passions . The land spirits sought refuge in the flowers , trees , pines and insects , while the marine ones in capes , promontories , reefs , seaweed , dolphins and seals . " " Five sirens , Caaibaté , Maci , Manipeya , Cuñataí and Alua who lived in the seas were transformed into the Cerro Verde , and into the capes of Fortaleza , i . e . Moza , Chato , del Barco o del Naufragio and Árido . Caaibaté , was a siren loved in the South and in the North , who loved the former and disdained the later . Metamorphosed into the Cerro Verde she suffers the eternal harshness of the North rejected lover , who , with the help of the sunrise and sunset , suppliers of sand , isolated her from the ground , by covering her with dunes . The South prevents this , by circulating , with the caress of his breath , the sap that comes from the heart of the siren in order to give life to the lush green vegetation that covers her , in a triumphant defense of love over hate ” . "