On the way to St. George's Castle, the cathedral itself does not need admission tickets, but visiting the chapel and treasure room requires 4 euros (2.5 euros each separately). Many beggars at the entrance are less tranquil than other churches. The former is the back of the Roman church before it is converted into a Gothic church, so it still has the decoration of the Roman church.
It's magnificent and solemn. Many art treasures can be seen. Like European churches, Lisbon Catholic Church, European first-class churches. The square is big. Watch out for thieves. While waiting for the bus, I saw a young Gypsy mother with a small child, a pushcart, who was actually a thief.