Fly into one of Southern California’s smaller airports—Burbank, Ontario, or Long Beach—and as the plane makes its final descent over densely packed enclaves you’ll notice impossible numbers of cobalt kidneys and cerulean quadrangles flecking the arid terrain. Though backyard pools are plentiful here, few live up to their initial promise—dreams of spa-like splendor fade into the stench of neglected chlorine—and ubiquity doesn’t necessarily translate to beauty. So rather than add yet another aqueous eyesore to an unassuming backyard in Santa Monica, architect Padraic Cassidy took a recent opportunity to make a seemingly simple pool the centerpiece of a larger backyard master plan.

The brief for the project was succinct: The client wanted a pool that was as big and as deep as possible. The property, however, proved problematic. The rectangular lot already housed a two-story wood-shingled home, a guesthouse, and a separate office structure. “The questions were: How close to the house could we put the pool, and how big could we make it without it feeling cramped?” says Cassidy, a Gehry Partners alumnus who launched his own eponymous firm in 1995. After casting away ideas of a lap pool along a long stretch of lawn, he divined a solution that, in hindsight, seems like the only viable option.

From the rear driveway, the entrance used most often, a tall gate opens to a path of seeded concrete, and the yard unfolds in an elegant hierarchy. To the left, a narrow lane leads to the office; to the right, a walkway turns toward the guesthouse. Straight ahead, the promenade ushers visitors to the main attraction: the large pool anchored at the edge of the home.

An ipe ramp climbs 30 inches from the path to the deck, which wraps around two sides of the pool. Inside, the water laps against the edges of the 29-by-31.5-foot rectangle, save for a corner notch and built-in hot tub. “The classic Neutra pools are very small, as little as 10- or 15-feet wide,” Cassidy says. “When making a pool with that as the reference, anything else is bigger.”

A solar-thermal system of black PVC pipes mounted on the roof heats the saline-treated pool—–with a bit of help from a midnight-black earthquake-friendly epoxy lining. “It adds that little extra heat and emphasizes the lagoon feeling,” Cassidy says. Looking out from just inside the back doors of the house, the sensation is heightened, the dark water rippling beyond the wooden “dock.”

Once in the pool, however, it feels a little more like the ocean. As with a shelf, the bottom drops quickly from three feet to the nine-foot deep end. A set of three long, shallow steps sits above the middle depth like a sandbar at high tide, the top tread covered with just a few inches of water. The two sides of the pool not edged by the deck stand as 8-inch-wide, 30-inch-tall tiled walls, which mitigate the grade change from the back of the home to the front of the guesthouse. Nearest the visitors’ quarters, the wall also acts to cordon off an outdoor foyer. “If the pool was on ground level, you’d open the guesthouse door and be forced to be part of what’s going on in the water,” Cassidy says. “Because the pool is at waist height, the wall creates a private space for the visitor.”

Across the path in the remaining yard, rocks and boulders flank a fire pit and outdoor lounge by landscape designer Tory Polone. The seats encircling the grade-level gas fire pit—an on-demand campfire—have become the resident’s favorite spot from which to take in the tableau. And, there, across the lawn, at the center of it all, is the pool—that rare sight that is as nice to look at as to be in.