On the edge of the old city so walkable easily. Seemed safe even when walking home late ( 11pm ish). Old city has plenty to see, a few supermarkets locally plus easy reach of the old major market for supplies.
Fabulous restaurants within easy walk. Easy to get to from the airport via the metro - cost about 8 euros for 2 of us and an easy 7 minute walk on the flat at the other end. Cost about 18 euros in a taxi from airport to apartment.
I would not hire a car for the city - we did 4 days in the city then got the metro back to the airport and picked up a car to continue our holiday further down the coast.
We hired fixed gear bikes near the small local glass covered market very reasonably and cycled around the city and down to the main beach - plenty of cycle ways and it felt safe - there is a wonderful dried up riverbed that goes around the old city right down to the city of arts and science - it has been transformed into the most wonderful green space for joggers. cyclists and pedestrians and you can carry on safely to the beach where there is a wonderful sandy beach and lots of restaurants.
The apartment is comfortable, safe and well equipped. The front door to the block needs to be treated carefully otherwise it will have your fingers but we were warned about this.
Apartment is on the second floor and there isn't a lift plus the beds are VERY low - think futon but nearer the floor- so possibly not the choice if you are over a certain age! ( we are 57 and 60 and managed)