Croatia's extraordinary island-speckled coastline is indisputably its main attraction. The first thing that strikes you is the remarkable clarity of the water. When it's set against a dazzling white pebbly beach, the water sparkles with a jewel-like intensity in shades of emerald and sapphire. There are long sandy and shingly stretches too – perfect for lazy days spent lounging and devouring trashy holiday novels. If that all sounds too relaxing, there are water-based activities at hand to lure you off your sun lounger – snorkelling, diving, kayaking, windsurfing and sailing, just for starters.