En route to the peak of The Carmel Bunkers (Bunkers del Carmel) in Barcelona, Catalonia, Spain.

On your walk up, you'll get a bird's eye view of La Sagrada Familia, the Palace of Montjuïc, Montserrat (a multi-peaked mountain range in Catalonia, Spain) and a panoramic view of the coastline. 

If you're on a tight budget and are looking for free things to do in Barcelona, visiting the Bunkers is an activity you'll definitely want to add to your travel bucket list.

Remember to BYOB - and a picnic if you like - because the views are incredible and you won't want to leave before the sun sets, trust me. The walk up takes around 15-30 minutes depending on how often you intend to stop for pictures.

Contrary to popular opinion, the Bunkers are a popular spot for couples, youngsters and backpackers. So be prepared to arrive earlier if you want to a secure a good spot with a great view of the sunrise or sunset.

If you're a morning person, I'd suggest going there for sunrise because it's a lot less crowded. However, if you're keen on watching the sunset, I'd suggest going there 

Thursday to Saturday between 20:00 and 00:00 because those are the timings when the 

Sagrada Familia will be lit up. Watching the sun go down and the lights come up all over the city, and witnessing the Sagrada Familia sparkle like a gem in the dark, will make Barcelona's night view all the more memorable.