Posavje, castles, spas and vineyards on the lower Sava

Posavje in one or two days

In a day, Brežice Castle in the morning, lunch at Bizeljsko and the pools at Čatež in the afternoon. With two days, I’d add Rajhenburg and Sevnica along the Sava and an evening stroll round Kostanjevica. Posavje has its own exits on the Dolenjska motorway, at Krško and Brežice, so it makes an easy stop on a trip heading on towards Zagreb.

Which castles to see in Posavje

The tourist board says Posavje has, for its size, the largest number of preserved castles in Slovenia, and mentions ten picturesque ones. Brežice, with its four towers, houses the Posavje Museum and a Knights’ Hall with Baroque paintings and fine acoustics. Rajhenburg Castle, at Brestanica, was built between 1131 and 1147 on a rock above the Sava and later became a Trappist monastery, where the monks made chocolate, cheese, liqueurs and sparkling wine. Sevnica grows 500 Blaufränkisch vines on its slopes, plus a cutting taken from Maribor’s vine, the oldest in the world. Podsreda stands in Kozjansko Park, and Mokrice beside a golf course.

Wine and turnip caves

Posavje is wine country too. It produces Bizeljčan, the northernmost Cviček and Blaufränkisch, and the tourist board singles out Miha Istenič’s sparkling wine. The most original sight is the repnice of Bizeljsko, caves dug to store turnips with around 200 years of tradition behind them, now used as wine cellars. With a slice of Bizeljsko buckwheat cake on the side, that’s the best meal in the region for me.

To sleep close to everything, search places to stay in Brežice on Expedia and filter by area before price.

Kostanjevica, Krakovo forest and Krško

Kostanjevica na Krki is the only Slovenian town on an island in the middle of a river. Beside it, the Božidar Jakac Gallery fills a 13th-century Cistercian monastery and is one of the biggest museums in Slovenia by exhibition space, with a park of wooden sculptures called Forma Viva. At the foot of the Gorjanci hills you can tour Kostanjevica Cave from April to October, and nearby is Krakovo forest, the largest lowland forest in Slovenia, all oak, hornbeam and alder.

Krško, the region’s most populous municipality with 26,210 people and 158 settlements, has the remains of Neviodunum nearby, one of the Roman towns on what is now Slovenian soil.

The Sava, the hills and the park

At Radeče you can ride the Sava on a wooden raft, a tradition 500 years old, and the tourist board rates the Radeče to Sevnica stretch as Europe’s finest fishing route for length and scenery. Above the valley, Lisca, 948 m, is a spot for paragliding, climbing and mountain biking, while Bohor, 1,024 m, hides four waterfalls over 15 metres high. To the north, Kozjansko Regional Park is a UNESCO biosphere reserve, with the Bistrica gorge, the best preserved in eastern Slovenia.

If you are short on time, see the best tours in Brežice and pick one that fits your day.

Terme Čatež and 92 per cent of arrivals

Posavska had 76,028 people on 1 January 2026, according to SURS, and 247,105 tourist arrivals in 2025. The striking thing is that 92 per cent of those arrivals went to a single municipality, Brežice, and the reason has a name. Next to the confluence of the Sava and the Krka lies Terme Čatež, the biggest thermal riviera in the country, with more indoor and outdoor pools than any other Slovenian spa, according to the tourist board. The region also has a second spa, Terme Paradiso.

A region with green credentials

Posavje takes sustainable tourism seriously. The tourist board has given Brežice the platinum Slovenia Green Destination label, Krško the gold and Kostanjevica na Krki and Sevnica the bronze. Krakovo forest, one of the most important wetlands in the country, has earned Kostanjevica the international Important Bird Area designation. And somewhere in the region grows Gašper’s chestnut, which the same board describes as the thickest tree in Slovenia. To me, those details say that nature here isn’t just scenery, and they’re a good reason to slow down, walk a little and look for birds rather than racing from castle to castle.

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