Very nice ride through Moravský kras (Moravian Karst). This area is a protected landscape to the north of Brno. It encompasses a number of notable geological features, including roughly 1100 caverns and gorges and covers an area of roughly 92 km². We started from the town of Blansko and after climbing up through a pleasant forest to the village of Petrovice, we enjoyed a long downhill ride.
The first cave we saw was in Sloup, but our goal was to see the Macocha Abyss. This abyss is 138 m deep and can be visited going through a long cave on foot and on a boat. This underground boating is an adventure not to miss, but you have to think about your visit early and reserve your tickets on line. The alternative is to go to the top of the abyss and admire this natural feature just by looking down to the big hole. And this is what we did. (OK, we came back and checked the cave and the boat ride. And it was worth it! Just come in the off-season time and reserve tickets online.) The ride up and down goes on the regular road, so you will encounter some cars on a sharp switchbacks. From the point 13 the road will bring you back to the starting point in Blansko.
The nicest part is the stretch from 6 to 7 through the sharp forested valley. However, due to its popularity you will meet a lot of bikers. On the other hand, on the part up to Sloup (point 4), you will probably not meet anybody.