Observatoire Ornithologique de la Durance" is located by the river Durance in Merindol. This discrete location on the upper side of a small hydroelectric dam has 243 species on the checklist.
We stumbled upon this location by pure chance. While driving along the D973 towards Cavaillon, there was a small sign for the observatory right before a roundabout in Merindol. We took a diversion but could not find it. Not very well marked, to say the least. However, later that day a little googling revealed details about the location, and since we were staying in the area, we made another visit a few days later, this time determined to find it. Following some narrow roads through residential and agricultural areas, there is a small parking lot and a tiny sign pointing towards the observatory. The hide can be found on the river bank a few hundred meters from the parking lot.
This location is best visited very early if the sun is out. Already at 8am the sun was at right angle from the hide. After noon the sun would be directly against the hide. The hide overlooks a wide part of the river, and the distance to the other side really calls for high magnification optics. Being the middle of May, breeding was in high activity. There were quite a few Great crested grebes around. Some were doing their dance thing, some were on eggs apparently, and some had small chickens on their back.
The river held quite a few Coots, various herons, cormorants, mute swans and mallards. A couple of black kites were resting on a dead tree on the other side of the river, and got nervous as we closed in along the path. It seems that everything always happens on the far side... The reeds held a few reed warblers calling, and Cetti's warbler could be heard as well. Above us a huge flock of swallows were feeding (mosquitos maybe - there certainly were enough of those, although not biting). There is a trail upwards along the river that ca be followed for a couple of kilometers. Butterflies and damselflies were plentiful. And in the top of the pine trees around the parking lot a few Crested tits were foraging.
The best periods to visit this location is January/February and April/May according to the "Visit Vaucluse" site.