BIG is mostly road adventure. I realised that Slovakia has an excellent proposition for GPS users on their race bicycles - nice and high tuned map of Slovakia
http://openmaps.eu/It has most of Slovakian asphalts and good gravels. All the highest (1200 m+) roads are perhaps included but some minor tarmacs like Sitno are not marked. Anyway it is a MILESTONE in free gps map of Slovakia. The real advantage of this map is a detailed set of altitude lines and autoroute navigation supply. It means that you can generate in just few seconds the altitude profile of every road marked on this map. Of course, if you compare the output with real data collected in terrain (like my webpage) there are some differents but never mind. Get it free and play :-)