Flat: There is a long promenade. In many places there are 2 lanes – a cycle lane and a walking path. It’s suitable for wheelchairs, baby buggies, roller-skates or just a leisurely stroll looking at the sea.
The Brits tend to walk by day -and Spanish are out in the evenings after 10pm.
Hills: if you want something more challenging, and want to see more of the local architecture, you can head up the hill to Mojacar Pueblo, and wander round the narrow streets and hills.
There are of course hills as a backdrop – so you can get a local map and head out …. without sounding like “nanny” – do take water with you!