Lake Jasień
Formerly known as Łupawskie Lake (area 577.2 ha, length 7.7 km, width 1.4 km, maximum depth 32 m). A narrow isthmus connects it in the north-eastern part with Lake Otnoga (area 15.8 ha, length 665 m, width 410 m, maximum depth 3.9 m). The largest and most picturesque lake in the Bytov region, it is situated in the Pomeranian proglacial valley zone. The bottom of the lake is lined with moraine dikes and limestone deposits. It fills part of a long trough used by the Łupawa River, which flows into the Baltic Sea from the northern end of the lake. Its shores are quite high, in places up to about 25 m above the water table, and largely forested. A narrow peninsula cutting deeply into the lake from the east divides it into two parts. There are 7 islands on the lake covered by a deciduous forest of oaks, ash, birch and alder. On one of the islands, among old oak trees, there is an early medieval stronghold. The highly developed coastline is varied by numerous promontories and bays. Both the reed-covered shores and the islands are nesting places for swans, cormorants, herons, grebes and other waterfowl. Black and red kites are also occasionally observed over the island. Until 1918, a white-tailed eagle also nested on one of the islands. In the south, it is connected with Obrowo Duże Lake (area 37.4 ha, length 1 km, width 520 m, depth max. 10.2 4n) and Obrowo Małe Lake (area 9 ha, length 520 m, width 270 ni). Canoeing trips down the Łupawa River, the wildest of the Pomeranian rivers flowing into the Baltic Sea, may be started from Jasień. Villages and settlements are located around Lake Jasień: Łupawsko, Otnoga, Zawiaty, Sieromino, Kłosy and the hamlets of Babia Góra and Obrowo.
Jasień village
A picturesquely situated holiday village in the midst of a wooded area, on the eastern shore of Lake Jasień. Good microclimate. Possibility of gathering undergrowth and fishing. One of the most interesting villages due to its Kashubian traditions and architectural monuments (on the road to Lębork, 18 km north-east of Bytów). In 1381 bought by the Teutonic Commandery of Gdansk. In the 15th century, it was a knightly village founded under the German law with 95 fields of land. In the middle of the 17th century, noblemen from Poland settled here. It belonged to the Ossowski family - one of the two wealthiest in the Bytov region. Buildings with a triangular crossroads square. The name of the village is probably connected with the dominance of ash trees in this area. The surrounding forests provided work for ash trees for many years, and in 1852 there was even a glassworks here.

There are several Group III listed buildings in the village, the half-timbered church from 1699, extended in the 19th century and called Manor House. It is a timber-framed building with a characteristic semicircular vaulted ceiling, one nave and a very low, squat tower. It has an interesting interior and the decoration of individual parts, of which the baptistery is the most noteworthy. Together with the bells, it shows the influence of Danzig art. In the cemetery there are decorative crosses made of wrought iron, the work of local blacksmiths, with shapes not found elsewhere.