Large open spaces are only on the waterfront, most of the streets are so narrow. Very similar to the old city in Seville.
We drove here only for 3 hours, but the city is nice, you can safely come for the beach holiday.
The symbol of the city is the "Castle on the beach", built in the 1940s. It's a mansion, not a real castle. There is even warning about this at the gate :) It was built for industrialist Narsis Plakh.
There are excellent walking paths on the green rocks on both sides of the beach, where we walked. If you like hiking, download here the brochure with maps.
Getting there: There is big problem with parking in the city, we parked at the beach here N 41 42.042 E 2 51.348. The nearest railway station is Blanes, then by local bus. From Barcelona there are combined tickets for the train + bus. You can also take the Safra bus from the Barcelona Estacio del Nord bus station or other cities (schedule). If you are in the airport, then check this website http://www.barcelonatransfers.com/en/.