Getting to Sintra is actually pretty simple. While most guidebooks will tell you to go to the train station attached to the Rossio station, from the Lisbon Marriott there is an easier way. From the Sete Rios metro station, there is another train station about 200 meters away. You can also take the train to get to Sintra from this station. In all likelihood, the train station at Sete Rios will be less crowded.

Quinta da Regaleira is a UNESCO World Heritage site located in the town of Sintra. It has only been opened to the public since 1998, as it has been a private residence prior to that time.
Getting to Sintra is actually pretty simple. While most guidebooks will tell you to go to the train station attached to the Rossio station, from the Lisbon Marriott there is an easier way. From the Sete Rios metro station, there is another train station about 200 meters away. You can also take the train to get to Sintra from this station. In all likelihood, the train station at Sete Rios will be less crowded.
In 1892, the property was sold to Carvalho Monteiro who wanted to build a fantasyland of sorts of his interests and ideas. The result is a maze of treasures at every turn.
Words can’t give the property justice, but there is a palace, chapel, park, a maze of tunnels, initiation wells, lakes, fountains and an aquarium.
The Initiation Wells seem to be the most iconic and picturesque of the entire property.
Rather than try to describe Quinta da Regaleira, I will simply let the pictures speak for themselves.