Underworld is a short, intermediate trail that should be a good ride for anyone who wants something flowy and interesting. That said, it’s only a small part of the connectors between some of Blue River Park’s larger loops. The trail leading up to it is paved, and it can be fairly easy to miss since there’s no signage showing the entrance. However, once you get into it, you can experience a few interesting trail features, such as two rock gardens, dips, rollers, etc., which is plenty for a 2.4 km stretch of singletrack.
The first trailhead is just on the BRP north loop on a tarmacked section with overgrown bushes just before it joins Blue River Park’s Hi-Fi trail. It’s a point-to-point trail, with the other end eerily similar to the first, with bushes growing into the tarmac.
While there aren’t any signs, it should be fairly easy to navigate once you start since there’s only one track with no side routes. It’s flowy from the beginning and takes you right next to the Blue River. As such, while you might not be able to see it, you’ll definitely hear it flowing next to you.
Like with the tarmacked section, you’re surrounded by trees and bushes throughout the trail. With that, there will be some roots in the trail that make for some exciting jumps.
There are also some rocks jutting out of the singletrack. You’ll have to pass through a very narrow section between two rocks in one section of the trail. Two of the rock sections are pretty gnarly but manageable, so you may be able to get through them on your bike. If not, you can hike the few steps to get through them since they’re no more than a few meters long.
Additionally, despite being flowy, there’s not much elevation change except for the small climb at the end.
Also, while classified as an intermediate-level trail, it’s probably manageable for a beginner wanting to get a feel for technical trails since it’s short and the technical sections are few and far between.
There’s not much to see on this trail, but the bushes and trees around you as well as the sound of the river, could be very calming.
The only recommendation for this trail is to try it at least once. After all, the 2.4 km stretch is quite fun and flowy.