The term Pantheon is a concession to the generally prevalent and popular style of neoclassical architecture, which is supposed to have begun explicitly in the 18th century, but was in use long before then in the Renaissance, a "rebirth" of classical civilization, especially in decorative ornamentation.

Originally a pagan temple, it utilized the principle of the arch to support a heaven-like surface over a public chamber, the rotunda.

The Roman Pantheon survived because it was quickly converted into a Christian church, like many other pagan public buildings.

The land and structures of the base were acquired by, and are administered by, the national government, today the Ministry of Defence.

For example, in the military legal system, the base is the headquarters of Juzgado Togado Militar Territorial Nº 22, "Territorial Military Court District Number 22," comprising Cadiz, with an address of Poblado Naval de San Carlos San Fernando (Cádiz).

The reservation was created from crown lands in the late 18th century by the last absolute monarch of the Spanish Empire at its peak, Carlos III, who had other dominions than Spain.

He donated the land for a base he considered an absolute necessity for the defense of Cadiz and of Spain, and then died.

Carlos III had already chosen as their patron saint, Charles Borromeo, the counter-reformation saint, who did his best to reform the church and lure the Protestants back into it, even sending a mission to Switzerland, origin point of the Swiss reform, to invite the Protestants there to return to the Catholic Church.

The judgement of Carlos III turned out to be perspicacious and sound as, a generation after his death, 12,000 Spanish with some English and Portuguese held Cadiz against a French force of 70,000 under Napoleon in the Siege of Cádiz.

When the French were gone, the savants who had congregated at Cadiz suggested a Constitution for a limited monarchy, but it was rejected by the monarch.

San Fernando has been lobbying to take over its lands for commercial development, a goose laying a golden egg for some interests, as former bases are in many countries, especially the United States.

The Ministry of Defence (Ministerio de Defensa) firmly reasserted its claim over the previous land of the base, and more.

On 12 June the Royal Decree (Real Decreto) was published in the Official State Gazette (Boletin Oficial del Estado, BOE).

No action could be taken, or any regulation or statute passed, no transfer of property, or any new use, could be originated without express permission of the Ministry of Defense.

The main structural elements used in the Illustrious Sailor's Pantheon are the arch, the vault, and the dome, all of which were in use in classical times, but generally not to the degree of elaboration shown in the great cathedrals and capitols of the Renaissance and after.

The wedge interposes the compression-resistant properties of its solid-state structure to change the direction and strength of a vector force transmitted by it.

The alternative structure to an arch, the lintel, or beam across the top of the opening, as in the many prehistoric henges, must support the load in a different way.

As the tensile strength of stone is much lower, the lintel under heavy loads typically breaks and collapses.

The inner and earliest Pantheon is a classic example of church architecture of the Renaissance, a time when the cathedral structure reached its floruit.

Small churches continued with the typical form evolved from a Roman house: a nave, or hall for the congregation with rows of seats; an apse, or special area facing the nave for the choir, the sacraments, statues or other images, and a stained glass window if one could be afforded, and the bema, a preaching pulpit inserted between in a lofty position appropriate to the power and authority of the church, believed to derive from the power and authority of God himself.

In Switzerland the great churches had been abandoned and stood vacant as monuments to vanity and corruption while the people worshipped in humble homes.

Typically of the absolute monarchs on the very doorstep of the Age of Revolution he had little thought for the cash he would have to outlay to obtain the outward form of the glory, to be the divine luminary on Earth shining benevolently over all mankind, if not as the son of God himself (as the ancient absolute monarchs had claimed) then at least as the sun of the Son.

If it had been completed along traditional lines the exterior would have shown vaults and arches with perhaps flying buttresses and a great dome in the center.

The inside walls form a splendid cathedral with arches, vaults, and domes (a main and some subsidiary), embellished with frescoes and larded with Baroque ornamentation.

The fact that the illustrious mariners earned their triumph by self-sacrificing words and deeds saves the monument from any such shallow and anti-Christian conclusion that only the rich go to heaven.

It conveys the highway out to Cadiz, but much of it is of sufficient elevation to sustain buildable land, which today it totally built over.

The government policy was only to place officers in the monument, but in some cases enlisted men were included anonymously in groups of remains known to have included the captain, and in at least one case the crown intervened to memorialize under his own name a seaman who had died for his country of wounds inflicted during an intense sea battle (see below).

In the mausoleum part of the monument, there is something like a tomb of the unknown sailor, a pool commemorating all those buried at sea, and a dedication to all mariners everywhere regardless of rank or educational status who served in the Spanish Navy.