DCR, you are probably referring to Montecito Hot Springs. It's up in the mountains behind Montecito just south of Santa Barbara. It used to be a grand and glorious resort in the 30s and 40's for Hollywood types. It was a beautiful building with many many concrete pools in beautiful wooden bathhouses behind the main house. The entire house and bathhouses all burnt to the ground during the 1964 Coyote Fire.
Now there is a very small pool -not really soakable. The water is privately owned and used for fire protection for residents on Hot Springs Road.
And I agree that Gaviota HS is only OK -nothing compared to Deep Creek or Little Caliente or the upstream pools at Big Caliente.