The "oehoevallei", translated as "eagle-owl valley", is located on the northern side of the large ENCI Quarry, south of the city of Maastricht. This quarry is very rich in marlstone and the area is famous for its fossils, like Mosasaurus and many squid-like creatures. The quarry is also famous for its inhabitants. Since 1998, Eurasian Eagle Owl breeds in the quarry and specifically in the small valley in the northern part of the quarry. Since 2010, this part of the quarry became a nature reserve, specifically to protect the breeding Eurasian Eagle Owl. They removed most of the forested parts in the valley and a large viewing platform was installed for visitors to observe this magnificent species.
Viewed from off the platform, the valley consists of very steep walls and a small pond in the center of the valley. On the left (east), large excavation tunnels are visible. The male and female tend to hide near the entrances of the tunnels between the bushes and small trees, which makes it a harder place to observe them. On the right (west), a steep wall is located. Within this steep wall, a large hole is present in which the Eurasian Eagle Owl breeds. You can observe them while they are on the edge of their nest, looking outside. When the young are bigger, probably at the end of the breeding season, they tend to leave the nest and "hide" themselves on the opposite steep wall of the viewing platform. Scan the walls and you'll find them. Another great view of the nest itself can be found on the eastern side of the area. From here, you can observe the nesting hole better and if young are present, they can be seen walking around from there.
The pond is a good spot for Little Grebe. The scattered bushes and small trees in the valley are great for species like Greater Whitethroat, Lesser Whitethroat and Marsh Warbler. Black Redstart can be heard singing too, its song echoing through the valley. Predatory birds tend to hang around the valley too, like Northern Goshawk and Eurasian Hobby. Often, Eurasian Eagle Owl react to the presence of these raptors, like looking at them or even scaring them off!
The valley is surrounded by forests and is also a good spot for many species of songbird and all five species of woodpecker are present, like Middle Spotted Woodpecker and Black Woodpecker. The forests are home to many common species, like Blackcap and Common Chiffchaff, but also to species like European Pied Flycatcher, Spotted Flycatcher and Common Redstart.
From off the viewing platform, you have a great view over the whole ENCI Quarry. This is ideal for observing raptors, like European Honey-buzzard, Red Kite, Peregrine Falcon and Black Kite.
The area can be easily accessed on foot and by bike. You can park your car at the Fort parkinglot (see map). From there, you'll have to climb a pretty steep road up towards the quarry. For invalids, there is a parkinglot on top of the hill so you won't have to climb the road.