Set on over an acre of beautifully landscaped, level grounds in Penn Valley, this exceptional 4,400+ sq ft residence was built in 1948 and beautifully expanded over the years. It offers 4 bedrooms, 4.5 baths, and a floor plan that unfolds with remarkable ease, with gracious formal rooms, a spectacular great room, elegant entertaining spaces, a private office, inviting outdoor living areas, and an in-ground pool. In the award-winning Lower Merion School District, this home has been expanded by two distinguished Philadelphia architects. Vincent Kling, AIA, designed the spectacular great room and conservatory addition, while Alvin Holm, AIA, created the elegant formal parlor and expansive primary suite, raising the roofline and enhancing both the exterior and interior architecture. A stone walkway leads to a charming courtyard entrance framed by a wrought-iron lantern arch. The center hall foyer introduces the circular floor plan, where each room flows into the next while maintaining its own distinct character. To the left of the foyer, the formal dining room is anchored by a handsome wood-burning fireplace flanked by custom built-ins and oversized windows overlooking the front grounds. The breakfast room is centered around a wall of windows that frames the pergola, lush backyard, and pool. The adjoining kitchen with butler's pantry offers generous cabinetry, abundant workspace, built-in appliances, bar seating, and views of the rear grounds. Positioned toward the rear, the office offers a work-from-home retreat with custom built-ins and views of the surrounding landscape. Across the foyer, the elegant formal parlor is one of the residence's most distinguished spaces. Warm and inviting, it features an antique marble fireplace, custom built-ins, and French doors that open to the conservatory. Bathed in natural light, the conservatory offers flagstone floors, walls of glass, custom built-ins, and garden views. A graceful circular staircase ascends to the primary suite above, while the conservatory opens directly into the spectacular great room, a space with rich walnut parquet floors, a striking wood-burning fireplace, custom built-ins, and walls of windows overlooking the pool and grounds. A full bath featuring a German glass shower enclosure completes the main level. One of the home's most significant expansions was the creation of the private primary suite wing on the second floor. Vaulted tray ceilings enhance the sense of space, while French doors open to a wrought iron balcony overlooking the front grounds. The suite includes a full bath with dual vanities and a walk-in shower beneath a dramatic skylight. A separate dressing area leads to two oversized walk-in closets and a dedicated laundry room with a brand-new full-size Samsung washer and dryer tower. Three additional bedrooms all offer abundant closet space and built-ins. A cedar closet completes the second level. Outside, the grounds are every bit as impressive. Unlike many Main Line properties, the land is exceptionally level, offering endless opportunities for recreation: a pergola, multiple seating areas, and of course, the in-ground pool, all beckon. A detached two-car garage completes the property. Recent improvements: new roof (2024), refinished white oak floors, fresh interior paint, new carpeting, new pool equipment (2026), gutter system, brand-new Samsung full-size washer and dryer tower (2026), updated conservatory windows, and numerous mechanical improvements. Homes of this caliber are increasingly rare-where exceptional architecture, beautifully usable grounds, and decades of careful stewardship come together. 723 Righters Mill Road is a timeless Penn Valley residence designed to be enjoyed for generations to come.