The Hot Spring:
Big Caliente Hot Springs are popular and have many "improvements" despite the long windy dirt road to get there. The main pool is directly next to the parking area that has a changing room, toilets, and is wheelchair accessible. The pool is a concrete box 3 feet wide, 7 feet long, and 4 feet deep with a ladder into the box on one side. The 115 degree F water is piped from the source flowing into the pool from a faucet that has a filter on the tip to catch algae from the source. The temperature can be controlled with the faucet, and is way too hot if left completely open. Technically this box is not clothing optional so be careful in case the ranger comes by.
Two more primitive and much more desirable creek side pools are located just upstream from the concrete box. The two pools are constructed with rock and mortar with a changing area and bench between the pools. Each pool is about 4-5 feet in diameter and 2-3 feet deep with a drain pipe from the bottom for cleaning. The source is up the hillside near some cotton trees and is pipes down to the pools keeping them at a comfortable 105 degrees F. The pools need to be cleaned often because of silt and cotton from the source, but a bucket and scrub brush are hidden behind a bush on the hillside.
The concrete box is very popular on weekends because of the close proximity to Santa Barbara despite the drive and rough road (but most passenger cars can make it if the weather conditions are good). This is why camping is banned within 500 feet of the parking area, but there are two official camping spots just a quarter of a mile away. Many tourists may be at the concrete box, but often the primitive pools with have genuine soakers, even if they are also packed. Despite there popularity on the weekends you can often have them to yourself on the week days. Even if you are alone the rules must be followed here because there is a designated ranger that lives in the area and checks the hot springs daily (in our experience with the ranger he was very mellow).