The longest route in Olszanica Commune Nordic Walking Park is a 9,3 km loop marked with black signs. The route partly overlaps the green route. We start from the bus bay in Zwierzyń and following a tarmac road along the right bank of the San reach Myczkowce Hydro-power Plant. We cross a bridge on the San and after reaching the pulse measurement point turn right. After a while we reach the Miraculous Spring. The spring, which spouts mineral water, has been visited by pilgrims since the 13 th century, on the Feast of the Exaltation of the Holy Cross. We walk on following dirt roads and reach the stairs which will take us to the dam in Myczkowce. We walk across the dam crest and following the route` signs head for Uherce Mineralne. Walking along a tarmac road and then a section of a historic cobbled road we pass Caritas Myczkowce Centre for Leisure and Rehabilitation. The Biblical Garden, or Gallery of Miniature Churches and Orthodox churches, which can be found on the premises, is surely a place worth visiting. Walking on we cross a bridge on the River Olszanka and turn left. After a while and having walked for 9 km we finish the walk in Zwierzyń, where we close the black loop. .