Cassiobury Park Cassiobury Nature Reserve (08/08/16) Posted by New to Watford on August 8, 2016 Some pics of the nature reserve between the park and canal in Cassiobury Park … The bridge into the reserve at the bottom of the park. The River Gade. The hide for wildlife watching. The Grand Union Canal. The bottom of the bridge over the canal appears to be a popular place for dog walkers, joggers and others to meet. Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)