sentences:  Through this he met Charles Forte, for whom he went on in 1964 to design the Serpentine Restaurant in Hyde Park, a series of mushroom structures inspired by umbrellas – which he thought appropriate in a park.It was demolished in 1990, but his smaller Dell Restaurant, built 1965, at the other end of the park survives, and the terrazzo terrace and built-in seating overlooking the Serpentine show his signature touches.The Serpentine Restaurant led to a commission for a restaurant addition to the Theatre Royal at York, where the mushroom structure was repeated around a sweeping, freestanding staircase.