Herewith a training lap for MTB through Sneek (source bikemap) of about 25 kilomter. The surface is varied, grass, gravel, shells and paved. There are several climbs via bridges, tunnels, and overpasses on the route.

Sneek has a number of forests/parks suitable for MTB cycling, however the possibilities are more limited than in, for example, the woods of Gaasterland or Appelscha. At 25 minutes drive you have beautiful forests to indulge in the specially constructed MTB routes.