Two possible ways run to Modrý důl (Blue Valley). From the centre of Pec hit the road towards Obří důl (Giant Valley) and immediately behind the parking place U Kapličky and the water reservoir Bukové údolí (Beech Valley Dam) take the route left to access the red hiking trail to Milíře and further to Modrý důl valley.
The asphalt goes steeply upwards, at the end of it you discover a gorgeous mountain valley with several quaint cottages that are included in the Protected Mountain Architecture List.
Alternatively you can go on along the blue trail to Obří důl valley. Behind Obří důl chalet, at the junction, take the yellow trail, cross the bridge towards Modrý důl valley (ca 1.5 km). There is an enchanting quiet place below the massifs of Luční and Studniční mountains. Go on to the waypost junction (you would come to it even via the turn by the reservoir), straight up on the red-marked "Železná stezka" ("the Iron Path").
While ascending, you will enjoy wonderful views of Modrý důl valley, Studniční hora mountain and Sněžka.
By Richter chalets, head on the green trail down to Pec pod Sněžkou. To avoid walking downhill on the asphalt road, turn to the red trail. There is a very steep descent but the following stroll through the valley along Zelený potok (Green Brook) is worth it.