Parc de Montjuic, Barcelona

I took the Bus Turistic at Barrio Gótico - for about 35min all the way up to get the cable car to go up to the Castle. 1 way ticket was 9eu the two way was 14eu. Honestly you can go down walking and take the time to stop and enjoy the views. The access to the castle opens at 10am and costs 5eu. I didn’t do it so can’t say much. The views in the cable car are beautiful! Then you can go down walking through the trails and through the fountains. Currently the night show of the fountains is suspended due to Covid. On your way going up to Montjuic this bus cover several nice spots such as : Palau Nacional, Poblé Español, MNAC (national museum of art of Catalunya - which currently has a Gaudí exhibition until March), fundación Miró and the Olympic Ring. I would say you can do Montjuic in half a day.

Amazing place on top of a hill with a picturesque overview of Barcelona! You can reach the top of Montjuic hill where the castle is located either by cable car or by foot. It is a 20-minute walk from the bottom. The cable car isn't that expensive and is pretty cool and a different experience, so I would recommend using it. Moreover, near the castle are positioned several different cannons and artillery which is also some kind of attraction. Also, the truly breathtaking Cacti Garden is located at the middle of the hill. It is one of the most amazing and peaceful places I have ever visited. Overall, Montjuic is a must see sight!