In a tour guide to Naples published in 1700 (Napoli Cittŗ Nobilissima, Antica e Fedelissima, Esposta a gli Occhi et alla Mente deí Curiosi, diviso in due Parti - Stamperia del Parrino, Napoli, 1700), Domenico Antonio Parrino described the premisesógardens, orchards, fountains and an artificial lake with gondolas to paddle about inóas "the grandest, most beautiful and delightful" such place in all of Europe. Interestingly, he was talking about a convent.
The convent of the Sisters of the Most Holy Trinity was built between 1608 and 1617 at the wish of sister Victoria de Silva, a noblewoman who had taken the vows. As sister "Eufrosina," she first took up residence in the convent of San Girolamo in Naples and then started her own order and convent on via Costantinopoli, both of which places are in the old historic center of the city. Pope Clement VIII, who reigned from 1592-1605, gave her permission to find larger premises for a completely new convent. (Irrelevant/irreverent note: Clement's main claim to fame was letting Giordano Bruno be burned at the stake in 1600.)
The new convent was built considerably away from the main part of the Naples of 1600, a site halfway up the Vomero hill, directly beneath the Monastery (now museum) of San Martino and the large vineyard and gardens of that institution. After the completion of the convent, work on an adjacent church was begun in 1618 under the direction of Cosimo Fanzago (1593ó1678), the truly tireless architect among whose other works in Naples are the churches of the Ascension at Chiaia, Santa Teresa at Chiaia, and Santa Maria Egiziaca at Pizzofalcone.
For two centuries, the convent lived a grand existence, a pilgrimage site for royalty from all over Europe, including one such episode in 1630 when Maria of Austria enjoyed wine drawn from wells (!) specially built to make her day at the convent less spartan. The church was rebuilt in 1737 after an earthquake, and things continued until the important year of 1806, at which point the new ruler of Naples, Murat, carrying out the wishes of his brother-in-law, Napoleon, closed all monasteries and convents in the Kingdom of Naples.
In that year, the convent was converted into a military hospital and remained such even after the restoration of the Bourbon monarchy in 1815. It continued to function as a hospital until relatively recently, and "l'ospedale militare" is the only name that the premises are known by to most Neapolitans. The church was damaged in the late 1800s and subsequently converted into a pharmacy for the hospital.
The location (below the present-day Corso Vittorio Emanuele overlooking the Spanish Quarter of Naples) and the fact that the site was essentially abandoned a few decades ago out of concern for the structural integrity of the buildings has meant that this gigantic piece of real estate has remained obscure to most Neapolitans. That may be changing; the grounds and convent are in the process of being restored, and a part of the grounds are already open as the "Parco dei Quartieri Spagnoli," providing a large terrace with a view over the city, a small playground, a stand of trees, and a large outdoor area with a cinema screen. What may become of the fourĖstory convent, itself, with its 28-arch sheltered portico (photo)óa museum or a theater are two possibilities that have been mentionedóis still very much up in the air, but the addition of more outdoor space for the residents of a cramped area such as the Spanish Quarter, is already welcome news.