This is a well maintained castle with 3 km of ramparts. It dates back over 2,000 years and conjure…read morevisions of troubadours and knights. History buffs should probably take a tour, but I was more interested in walking the grounds. I took a one hour train ride from Toulouse. I recommend staying elsewhere and visiting the castle as the city itself is not a stand out culturally and architecturally. From the SNCF station it is about a one mile walk to the Narbonne Gate in the Old City. I used AllTrails to navigate the castle as it is large and it is hard to distinguish where you are otherewise. It took me 90 minutes to walk the circumference of the lower outer gates and the inner city. The castle is FREE but the ramparts are ticketed.
Advice:
Everyone told me the food is not good here so pack a lunch and eat at the walls or the park at the gate. Many restaurants in the city if you choose otherwise.
Sunscreen if it is a sunny day.
If you take the train, there are markets along the way even on Sun.