Try here as it sounds like it has everything you want including neighbouring villas for rent with the other family, beautiful beaches, pools and amenities on a luxury family resort (for £250 a week!)
There are comments from other families. beachwise the Mar Menor is one of the largest inland lagoons in Europe, creating miles and miles of beaches in addition to the Mediterranean coast. The Mar Menor is about 12 miles long by 6 miles wide and it is very shallow and calm. It is saltwater and because it is shallow it warms up quickly and in the summer the water is a tropical temperature. The beaches around the Mar Menor have lots of play areas and are perfect for families or for those who want to be close to cafes or shops.
5* Crowne Plaza Luxury Family Resort Special rate of £250 a week for bookings taken this year! Polaris World's la Torre Golf Resort -18 hole Nicklaus designed golf course -Play areas, swimming pools, tennis courts, day care centre, restaurants, health spa and gym -15 minutes beach (Blue Flag Mar Menor Beaches favoured by families for shallow -10 minutes Murcia airport -Townhouse 2 bed 2 bath, dining patio & 2 solariums. Sleeps 5 -Fully secure private outlook overlooking golf course -There is more than one available if you want to go with friends or family