St. Paul's Cathedral in Liège, a stunning example of Gothic architecture, offers free general admission, though a small fee (typically €3-€5) applies for access to its rich Treasury, home to significant religious art and artifacts like the Mandylion of Liège. The cathedral is generally accessible for the main nave, but some older sections or the Treasury might involve steps, limiting full accessibility; it's advisable to check specific needs with the venue. Visitors can easily explore solo, and a typical visit, including the Treasury, lasts 1 to 1.5 hours. It operates year-round, but hours may vary by season or due to religious services, so checking current schedules is recommended. As an active place of worship, respectful attire is appreciated.