Welsh Valley was built 1957-58 on land previously owned by Percival Roberts, Jr., former president of the Pencoyd Iron Works. The property, known as "Penshurst" and once considered Lower Merion's most lavish estate, was started by Percival Roberts, Sr. In 1860 he acquired 160 acres in the present Penn Valley. At his father's death in 1898, Roberts, Jr., inherited this land. Soon after, he significantly increased his fortune, leading the Pencoyd Iron Works through its evolution as the American Bridge Company to make it the leading supplier of steel for bridge construction in the country. In turn, Roberts continued to purchase land to add to the size of the estate. By 1901, Pencoyd had merged with the giant U.S. Steel Company and Roberts became one of it directors. At this time, the family property had grown to 571 acres and Roberts and his wife, Bessye, began to plan their house.
Roberts announced that he would build a house and a conservatory, each to cost $50,000, but the total amount for the seventy-five-room mansion was thought to be well over $3 million. Boston architects Peabody and Stearns were selected, and George F. Payne and Company of Philadelphia was given the contract to build it. Roberts had decided to use an Elizabethan style, and the architects were dispatched to England to study such houses as Longleat and Hardwick Hall. Much of the wood and ornamental hardware were antique, imported from England. Floors were teak. The magnificent mansion, built high on a steep hillside (just to the northwest of the current Welsh Valley), was visible only from a small opening in the stone gates that lined Conshohocken State Road. Its banks of bay windows were outlined with white, as were the quoins, the tops of walls, and the banisters of the graceful stairs descending on either side to the fountains and pool below. The house, perfectly reflected in the pool, faced southwest over spectacular gardens, with colorful rock plants and specimen plantings filling the rising hillside.
When completed, the house was the centerpiece to a vast working farm where dairy barns for the Ayrshire herd were immaculately maintained, with veterinarians on staff, and dozens of farm workers. But while Penshurst may have fulfilled a role signifying both business and social prominence, it never was used to its fullest. The Roberts did very little entertaining. Sadly, their two sons died at an early age probably of scarlet fever or diphtheria. Thereafter, Percival and Bessye led quiet, relatively unpretentious lives considering the luxury of their setting, and seem to have found their greatest pleasure in the gardens and farm.
By the late 1930s, Bessye was quite ill and Roberts had grown increasingly angered as he heard of plans for a Township incinerator whose tall smoke stack would be in his view. Although he tried to block the project, he was not successful. When the incinerator was built in 1939, Percival and Bessye moved to a large suite at the Bellvue Strafford Hotel in the city, where live-in nurses and servants attended to their needs. That year Roberts filed for a permit to demolish the house. He made good on his threat, first selling interior paneling and the artwork, but leaving elements of the garden, summer houses, fountains and gates.
At his death in 1944, the land and Roberts' estate were bequeathed to the Roxborough Hospital and the Children’s Seashore Home. The hospital in turn sold it to Home Life Insurance Company, whose owner for many years maintained the Japanese rock gardens, a favorite place for a Sunday stroll by Lower Merion residents. In the 1950s, much of the land was sold to developers, including a 33-acre parcel purchased by Lower Merion School District for the District's 3rd junior high school (the others were Bala Cynwyd and Ardmore).
The District contracted the architectural firm of Harbeson, Hough, Livingston, & Larson to design the new school, which would serve students grades 7-9. The general contractor was Frank. H. Wilson Co. The principal architects were well-known throughout the Philadelphia area, particularly for work on the Ben Franklin Bridge, Rodin Museum and Thomas Jefferson University. For Welsh Valley, the architects chose a campus-style design consistent with concurrent work on the District's new Harriton High School (which also opened in 1958). The facility would incorporate several one and two story buildings connected by covered walkways. Major renovations and additions were made in 1998-2000, including two new buildings to connect pre-existing buildings and allow for interior circulation on the campus.
Additional Notes: Welsh Valley Junior High School became Welsh Valley Middle School in 1978 as the District consolidated its three middle schools to two; Ardmore Junior High School closed at the time due to decreasing enrollment...Today all that remains of the former Penshurst are the gates along Conshohocken State, a large mid 19th century house and several farm buildings and outbuildings.