Sadly I made the mistake of hiring a car when travelling to Sintra. Please do not take a car anywhere nears this place you will never get parked (and we visited in the off season). Disappointed with not being able to park up to see the more famous places in Sintra we went a drive and randomly came across this place with a car park. We didn't know anything about it and though we would visit as couldn't visit the other places we had planned to.
This place is well worth going to see. Was less than 20 euros for two people to visit. We walked the whole garden before visiting the palace. The palace has been restored over the last few years and is stunning.
The site also has a small shops and café which was reasonably priced.
All in all this saved a wasted drive to the area. One comment I do have is the gardens aren't suited to people with mobility issues.More