Hotel San Antonio in Puerto Del Carmen, Lanzarote. The hotel is right on the beach and the only other access to this part of the beach is from walking around the shoreline from the main beach at Playa de los Pocilos which is to your right if you come out of the main hotel doors.
There are 2 pools, the one down below you can walk straight onto the beach from and there is another at a higher level which overlooks the beach. There is a hotel run kids club with lots of activities, water polo, archery and football on the beach etc. There is also a room for the smaller children where I think they go to do other activities like drawing and there is also a play area with slides etc. There is a mini golf course directly opposite the hotel which also has trampolines and there is a mini golf next door to the hotel on your left.
You can book this through Thomson and if you have a look at their online brochure you can see the view from the hotel etc. The hotel also has their own website but I can't recall what it is.