Anyone who likes to tinker is well acquainted with the way that building projects — whether they involve cars, computers, furniture, whatever — tend to take on a life of their own, turning out to be larger and more complex than the hobbyist had originally intended. For one antiquarian on the outskirts of Barcelona, though, this doesn’t even cover the half of it.

Jacinto García was born a farmer’s son and worked as a wine merchant before settling into the antique game. By the 1960s he was living with his family in the Les Fonts neighborhood of the industrial suburb of Terrassa, engaged in a brisk trade of selling furnishings salvaged from old houses and farms. His mother thought it’d be fun to remodel the house — a simple two-story affair, quite typical of the neighborhood — in the style of a medieval castle. A little exterior decorative work, maybe a small addition with a few sculptures and tower-like elements, something along those lines. Nice little project for Jacinto to work on around the house, right?

Well. What started as a refacing of the house in brick and stone and the dense incorporation of medieval ornaments such as niches, busts, gargoyles, and wrought iron, steadily carried on into the creation of additional stories, towers, columns, walls, and eventually the purchase of adjoining land to massively expand the building into a full castle complex complete with watchtowers, parapets, baileys, defensive apertures, and numerous halls. This work, stretching as it has over five decades, has all been done personally by Jacinto García – who, before starting this project, had no background in architecture or construction – with help from his wife and, in later years, a few assistants.

Little is known about the interior of Les Fonts Castle, since it is, after all, a private residence and not open to the public. One report suggests that much of the complex — which takes up one full block — is used by the Garcías as a warehouse for their antiques. Because the expansion began in the 1960s, before things like zoning laws or building permits were in much force in Terrassa, there is a great deal of speculation as to what will happen to the castle after Mr. García dies; municipal plans to improve Les Fonts might be difficult to rectify with the hulking post-industrial fortress towering over the neighborhood.