I’ll add what knowledge I have to this since this is my backyard (not literally, just live up the road ;)). I’ll do my best to describe the trails as I’ve been on all of them but not on a bike as the majority of them are impassable on anything but 2 - 4 legs (when I had dogs).
Best entrance is behind the Mt Uniacke Fire Hall (654 Glooscap Trail (hwy#1)) as the main entrance to the Estate gets locked at dusk.
The Trails -
Wetlands Trail - Very difficult even by foot, extremely overgrown, next to impossible to even find the trail markers anymore. EDIT: apparently it’s been cleaned up and is passable. Nice raw technical lines according to bent6543.
Barrens Trail - Very difficult even by foot, extremely overgrown, next to impossible to even find the trail markers anymore. EDIT: apparently it’s been cleaned up and is passable. Nice raw technical lines according to bent6543.
Old Halifax Rd - Very wide open, easy to follow, lots of rocks and the occasional downed tree. Excellent for beginners but intermediate and advanced riders might find it a bit boring. Can be very icy in winter and very sloppy on the shoulder seasons.
Hothouse Hill Loop - Very short but can be a real blast for beginners with a very moderate climb and then a quick little bit of singletrack back down to the estate, good for a few laps. Again, excellent for beginners but intermediate and advanced riders might find it a bit boring.
Lake Martha Loop - This is great for families as it’s pretty much just a crusher gravel walking trail for the tourists visiting the Estate.
Red Spruce Loop - The waterside part is very rooty and the elevated half can be overrun with fallen trees and overgrown. It’s doable for the intermediate and advanced riders, for beginners, expect a fair amount of hike-a-bike.
Drumlin Field Trail - Fairly smooth groomed walking trail with a bit of rooty trail along the water. Good for beginners and families.
Murphy Lake Trail - Fairly smooth with a few roots and rocks but nothing serious. I’m not sure that this trail exists anymore east of the Firehall as I’ve never gone in that direction or even remember seeing a trail. I use the west portion to make my way to the Estate.
These trails are used regularly by people and dogs, and although dogs are supposed to be on leash, nobody here adheres to this rule. In the 8 years I’ve lived here I’ve rarely seen another bicycle so please be cautious using the trails. I would say these are great beginner trails as they are fairly wide and with nothing too technical so they can definitely help to build confidence. I would classify myself as a beginner so I enjoy myself and the ability to just pop up for an hour or so when I get a chance. Hope this helps and contributes.