Against his will, Ponce de León, then governor, agreed to move the capital from Caparra to San Juan in 1521. Very quickly the new town took shape. Houses made of wood or brick with tile roofs lined four distinct dirt roads. A new home, Casa Blanca, was erected in 1523 for Governor Ponce de León and his family.
The Bishop Alonso Manso chose the location for the Cathedral of San Juan and work on it began immediately. After his death in 1539, a hurricane destroyed it completely. In 1540, reconstruction of the building was begun but this time with stronger construction materials. It was a grand undertaking and one of the few examples of medieval architecture in America. The reconstruction was interrupted when Bishop Bastidas, the director of the task, left for Santo Domingo. The next bishop, Diego de Salamanca, ordered further work but changed the style to Gothic Plateresque. It was not until halfway into the nineteenth century that the Cathedral was finally completed.
In 1523, the Church and Monastery of Saint Thomas Aquinas was begun. Ponce de León gave the friars the land where they were to build their monastery. The actual building of the church now called San Jose began in 1532, even though it took many years to complete. The section erected in 1532, The Main Chapel or Sanctuary, is an example of Isabelline Gothic style, especially in its stelliform dome of stone blocks. The Sancturay was finished in 1539. This church was destined to be the burial place for Juan Ponce de León and all of his descendants. Ponce de León remained buried in the crypt at San José from 1559 to 1836, when his remains were exhumed and later transferred to the Cathedral.
Because of the increasing interest on the part of Spain’s enemies, England and Holland, Puerto Rico became a target of attacks of these two countries. The Mexican Situado, which was the shipment of great treasures from Mexico, was brought to San Juan periodically. The city was subsequently attacked in 1595 by Francis Drake and in 1598 by George Clifford; both attacks were unsuccessful. Things were different when Boudoin Hendricks bombarded the city in 1625, with seventeen ships. This was the worst attack the city had ever experienced and it was followed by others on a smaller scale.
The attacks on the city prompted the building of huge walls that connected the two main forts, El Morro and La Fortaleza, and also enclosed what was the city of San Juan in 1630. The city at the beginning of the seventeenth century was composed of three hundred houses, one hundred and twenty huts or bohios, sixteen hundred Spaniards and two thousand mulattoes. The walls were finished in 1639, and with the completion of the walls, the city became a fortress and a Spanish watchpoint in the Atlantic, even if Spanish supremacy on land or sea was on the decline. The walls were made of limestone, mortar, and sand. The thickness of the walls varied from twenty feet at the base and twelve feet at the top. Engineers and architects were brought from Spain to design and direct the huge undertaking.
San Felipe del Morro, named in honor of King Phillip II, provided little protection to the city in 1540 when construction began. In 1591, major defense work was undertaken to protect the fort from inland attack. It proved unpenetrable to the attack by Sir Francis Drake in 1595. It fell to Earl of Cumberland in 1598, who approached the fort by land but was driven out by an epidemic of dysentery. In 1625, the Dutch under the command of Boudoin Hendricks took over, ransacked, and burned the city but could not enter the fort and consequently left.
The other fortress, La Fortaleza, was authorized to be built by Charles I as a defense against raids by Carib Indians. It was completed in 1540. The fortress proved to be of little value as a defense post, and it became the official residence of the governors and their families. It was twice occupied by invaders, the Earl of Cumberland in 1598 and the Dutch General Boudoin Hendricks in 1625. La Fortaleza is the oldest executive mansion still in use in the New World.
Just to the north of La Fortaleza is the San Juan gate. This gate opened to La Caleta de San Juan, a narrow street which led up to the Cathedral from the harbor. Travelers of the sixteenth would walk up La Caleta to the Cathedral to give thanks for a safe journey. There were a total of six gates originally but only two remain today after the walls were torn down allowing for the city to grow.
Facing the Plaza de Armas, one of many in the city, the alcaldia or city hall, was constructed in stages beginning in 1604 and ending in 1789. The city hall resembles Madrid’s city hall with its double arcade. The Plaza de Armas was planned as the city’s main square. Here the soldiers would practice defense drills. The plaza fulfilled the Spanish sixteenth century requirements in size and purpose.