There is a great difference between the northern Costa Blanca and the southern Costa Blanca locations. The south has a very hot climate, the terrain on the coast is very flat. The sandy beaches are excellent in quality.
The North Costa Blanca is where the terrain starts to change, you start to see more mountains only just inland and hills start to appear – once you get past Benidorm all of a sudden you see green everywhere where before it was dry and barren.
Many people like the northern Costa Blanca – it reminds them of the green northern European country from where they came. Certainly the beaches are not as nice but they are still sandy and of great quality. In this area you will find multiple cliffs, coves and some rocky beaches for adventuring.
However the southern Costa Blanca tends to have coastal towns that very much centre around the beach, so you have many high rise apartment blocks just off the beach area. In the northern Costa Blanca towns spread further inland and tend to have scores of villas littering the pretty green hillsides. Inland you have green valleys full of orange groves and vineyards full of bustling little villages and towns.
While the northern Costa Blanca is prettier and more scenic it is however much more expensive and it is much further to the airports. My advice would be this: if you just want a second home for a getaway, consider the southern Costa Blanca. It is built up – therefore there are loads of restaurants and bars within walking distance. The beaches are superb and most importantly, either Murcia airport or Alicante airport will be practically on your doorstep, so you only need to get a taxi which eliminates the expense of car hire.