If you are going to take the AVE high-speed rail line at the Barcelona Sants, the Mercadona car park, located on Avenida Roma 22, is only 3 minutes walk (300 meters) from the station and is one of the best options.
You can park comfortably into its wide spaces (up to 3.5 m) with very easy maneuverability, in a closed and covered area for vehicles with a maximum height of 2.20 m.
The car park is attended (remotely by a staff who speaks up to 5 languages) and 24 hour-monitored by CCTV and permanent intercom system.
From Monday to Friday, between 7:00 am and 8:00 pm, only ecological vehicles and those with the environmental label B or C of the Spanish Traffic Authority -DGT- are allowed to circulate here. Vehicles registered outside Spain are not classified according to the environmental criteria of the DGT environmental label. To drive there without being ticketed, all foreign vehicles must register and pay the corresponding tax. Further information: http://bit.ly/ZBE_BCN_en Permit registration: http://bit.ly/ZBE_BCN_EN
This car park is always open (24/7).