Could you join that park onto the s. Juliens wood map?
afraid I've not seen the St Julian's map. Hopefully the SWOC mapping officer could provide...
Not in answer to your question - I think that most of Newport would be pretty good for proper urban races (with proper hills!) as lots of nice parkland and scope for route choice, but as there's not the interest locally it's being kept a long way down my list (well, below Monmouth...) before I give it any more thought!