The easiest way to reach the Areuse Gorges is to take the tram to Neuchâtel and then the train to Noiraigue. From there you will start to walk through the Areuse Gorges back to Paradis Plage.
"After 30 minutes of walking, the walls close in, the descent starts and the sound of the torrent gets louder. We cross the first footbridge over the bubbling water. Through the metal mesh of the deck, we can feel the swirl of water under our feet, the force of it tumbling and surging into chasms. There’s a wide variety of wildlife: we spy a dipper, a timid bird, playing in the eddies lapping against the rock he’s perched on. At Champ-du-Moulin, trout swim up the current. We continue the descent and it would be so tempting to slip into the clear blue-green pools. Let’s not forget we’re in the Jura... brrrr!". More information here.