Pohorje massif offers a lot of easy hikes of different nature. The valley of Bistrica is very nice and due to its granite rock basement a special one in Slovenian mountains. It is good to visit it whene there is a lot of water.
From Slovenska Bistrica you drive along the creek towards the NE (follow the inscriptions: "Vintgar" (=gorge)) some 4 km and park at the end of the road.
It is possible also to arrange the tour as bike & hike. In that case you would prepare in advance bikes on Pohorje plateau. A good option is the shurch of Sv. Urh, near the scattered settlement of the same name. You drive up there by this route: Slovenska Bistrica - Veliko Tinje - then soon north of the village you deter right and follow the iscriptions to Sv. Urh church.
From the parking place you continue along the nice creek. The path is good and comfortable, all the time marked. Don't leave the path, stay in the gorge, slose by the creek. After some 30 min you reach the place, where on the other (orographically left) side of the creek once was an Ancient Romans quarry. You continue up the creek, steadilly gaining the altitude. In next 15 min you reach the first waterfall. The path deters right to it (inscriptions). Slap Šum has some 15-20 meters. After seeing it, you return back on the main path and continue up the valley. The gorge becomes more and more beautiful. In some places quite narrow and rocky, in other places flat and even sunny. In some 20 minutes you pass the picturesque second waterfall, then pass a few ruines of old mills and finally reach the Štampohar's mill.
The flat part of the valley
Exiting on meadows near Marolt farm
From there it's good to continue a bit more up the valley, which is really nice there. Then you reach the crossroad by once famous Marolt Spruce. The giant tree is nowadays fallen, but you can stuill admire how big it was once. From that crossroad you can either continue by the valley up to Močnik farm (and from there return to Sv. Urh by the road), or exit towards the south (not marked) on meadows below Marolt farm. Sv. Urh church is not far away (a bit higher) - you reach it by the farm road. From the parking place it's some 3 h to ascend till here.
Good shoes, poles and eventually a bike.