If you find yourself walking the streets of Old San Juan, you may be surprised to come across an extraordinarily slim, two-story house known as La Casa Estrecha. Measuring a mere five feet, three inches across, the house was once a neglected alleyway before it was transformed into a habitable abode by architect Antonio Álvarez.

Ensconced between two regular-sized buildings, “The Narrow House” draws visitors to tour its surprising dimensions. Its facade features a vibrant yellow hue and a lush green door, making it very hard to miss! Álvarez bought the house when it was a “complete ruin” and according to this video, the design is all his own.

Despite its slim stature, the house has all the basic amenities of a home, including a living room, dining room, kitchen, bathroom, and bedroom. The bathroom’s design, however, is a bit tricky: without enough space for a separate shower area, the floor was fitted with a drain under the sink area, so all the washing goes down in one spot.

“It was a great challenge to design this space because the stairways [had to be placed] in very strategic parts,” Álvarez says on the video tour. The custom stairwell features alternate steps that extend the height of the house, because traditional steps just wouldn’t work in such narrow settings. Today, Álvarez uses the house as a gallery to showcase local artwork.

It may be the narrowest house around, but a small balcony on the top floor opens to reveal a magnificent wide-angle view of the San Juan Bay and the colorful streets of Old San Juan below.