Yes, you absolutely need a ticket to enter the Castelo de São Jorge in Lisbon, Portugal. As of 2026, the standard adult ticket costs approximately €15, with discounts available for seniors, students, and families. Residents of Lisbon can often enter for free with proof of address. Because it is one of the most visited monuments in Portugal, the ticket lines can be extremely long, often exceeding 45 minutes during peak summer hours. It is highly recommended to purchase your tickets online in advance through the official website to skip the primary queue. Your ticket grants you access to the castle's fortified walls, the archaeological site (featuring Moorish ruins), the "Camera Obscura" (periscope) which offers a 360-degree view of the city, and the permanent museum exhibition. Note that the castle is a steep uphill walk from the downtown area, so many visitors take the famous Tram 28 or a "Tuk-Tuk" to reach the entrance before presenting their pre-booked digital tickets.