Just back from Malaga/Torre Del Mar/Nerja on Wednesday, can't recommend enough!
Malaga is beautiful with a nice long beach that stretches right around the bay to the east of the city, nice and cheap to eat and drink as well.
There's a service bus that runs along the coast that could take you to the coastal resorts of Torre Del Mar & Nerja, Malaga to Torre Del Mar is a 40 minute journey costing 2.70 euro one way.
Malaga must be served by every airport in the UK and we rented a small, very clean studio flat right in the center of the city for 60 euro a night.
At the minute the area is still very traditional Spanish but my father in law who lives there is starting to complain it's becoming 'more like Benidorm every day' 🙂
Nobody gonna mention Copenhagen? Nice beaches a 20 minute train ride from the city centre. Plus swimming in the harbour.
Not long back from Spain (Palma, Majoca) and I've not seen it this heaving this early in the season. Perhaps people are taking earlier holidays this year due to the long winter, but I flew out and back at 6am and airports both in blighty and spain were packed, I dread to think what it will be like in peak season if demand increases.
I'd be tempted by Bordeaux - not exactly on the beach, but near some very nice beaches.
Tarragona, watch out for pickpockets at busy times.
