From August 12-14 2024, I drove to the southern part of Belgium to visit the Viroin Valley area, mainly looking for butterflies. Then I drove to Luxembourg to spend two days there looking for any other wildlife I could find. Luxembourg was not yet listed on my website as a country where I photographed any animals, so it was about time I went there.
On the way home on the last day I visited the beautiful Holzwarche Valley in Belgium, near the German border.
Below are the locations that I visited.

Belgium
Viroinvallei 
In the south of Belgium lies the Viroin-Hermeton Nature Park (GPS: 50.073682, 4.573638), better known as the Virvoin Valley. This western tip of the Belgian Ardennes is famous among nature lovers. The chalk grasslands are full of wild orchids. The exceptionally rich flora attracts a large number of special butterflies. And then there are the gorges, mini canyons, the special limestone rock formations and the caves. The mix of extensive deciduous forests, moist meadows and calcareous grasslands make the area unique. The ideal base for the Viroin-Hermeton Nature Park is the pleasant village of Nismes (Tourist Info: GPS: 50.074424, 4.548048). 
Various walks through the area start from here. I walked the yellow route to La Roche aux Faucons (7.7 km, start at the church: GPS: 50.074841, 4.548479). Here are the most beautiful limestone grasslands in the region.
My best sighting here was a mating pair of Chalkhill Blues near the special rock formations of Fondry des Chiens: GPS: 50.069451, 4.556210.

Holzwarche Valley
The Belgian Ardennes and the German Eiffel are known for their natural beauty. A gem in the east of Belgium, right on the border with Germany, is the Holzwarche Valley. This nature reserve is located at an altitude of approximately 600 meters and has an area of 75 hectares. The Holzwarche is a small river that originates nearby. Traditionally, this involves extensive management of the hay fields. At the end of the last century, the hay fields were under great pressure due to overgrowth and the planting of spruce plantations. Fortunately, the tide has turned and the area of hay fields is still expanding. And those hay fields are teeming with special butterflies. A walking route has been laid out through the area and invites you to enjoy a day or weekend of wonderful bird and butterfly watching in the Holzwarche valley.
The Holzwarche valley is located between the towns of Büllingen and Rocherath in the east of Belgium. You're suddenly marching into Germany here. 
For a walk through the Holzwarche valley, it is best to park your car at the Enkelsberger Mühle (GPS: 50.423473, 6.302089), a sawmill between the towns of Rocherath and Mürringen. Walk upstream to the German border. Here you walk through the raised moor with a very rich flora and fauna.
My best observations here were Goldcrest and a Eurasian Red Squirrel.

Luxembourg
Brucherbierg-Lallengerbierg Nature Reserve
Between the municipalities of Esch-sur-Alzette, Kayl and Schifflange, the Nature Reserve "Brucherbierg-Lallengerbierg" (GPS: 49.486650, 6.003489) extends over approximately 267 hectares. You can walk, cycle or mountain bike there. Parking: GPS: 49.485930, 6.003945. After the cessation of mining, which was located in this place, the area resembled a moonscape with bright red soil: no vegetation, a barren, dry area. Little by little, nature has reclaimed its space. The rocky bottoms are again overgrown with dry grass, bats have settled there and many different species of butterflies can be admired among the orchids. 
My best observations here were a Blue-winged Grasshopper, Grayling and also here Chalkhill Blues.

City of Luxembourg
Although it was not my plan beforehand to go to the capital, I decided to do so anyway because I was in the area. And that turned out to be a good choice. The city is beautifully situated and has a historic old part within the old city walls. The city consists of a low and a high part. Down in the green valley flows the river Alzette, which splits the city in two. I took a nice walk along the river where I photographed a beautiful Banded Demoiselle.

Haff Réimech Nature Reserve
Haff Réimech wetland in the south of Luxemburg is a 300 ha old gravel pit area of which 100ha are classified as nature reserve. It is a Natura2000 zone and one of Luxembourgs two Ramsar-zones. Haff Réimech is Luxembourgs premium birding area: out of the 330 species observed in Luxembourg, 260 have been seen here.
The best option is to start at Biodiversum nature centre: GPS: 49.492773, 6.362137. From here I followed a trail in a loop with several bird hides.
My best observations here were a White-legged Damselfly, a Sloe Bug and, for Luxembourg, the rare Great Crested Grebe.

Schlammwiss Nature Reserve
The 375 ha large wetland reserve Schlammwiss in Uebersyren is an important migratory stopover for a great amount of birds, which use the wetlands to refill their reserves. The area has marshes, patches of forest, agricultural lands and orchards and Schlammwiss has with almost 20 hectares one of the biggest reed banks in Luxembourg.
I parked closeby, in the village of Munsbach and explored on foot: GPS: 49.631669, 6.269273.
When I was here, I didn’t see much except for quite a few Ruddy Darters.