Ok sorry, not at work now, been sitting professional exams all day so apologies for the clipped answers, done in the break.
So know the area reasonably well, we live in Swindon so not too far and often go there at the weekends.
Who's on the trip, just you, you and a partner, children, dog? How far do you want to travel? Do you like to walk or short walks from the car?
When are you going? If soon then it may be weather restricted.
Slimbridge is about 50-60 mins away from lydney, but would be a good all day place if the weather isn't good. If you do go, consider the Bell inn at Frampton on Severn for good food, (
http://www.thebellatframpton.co.uk/) or if you're feeling flush and lve fish, The Old Passage Inn at Arlingham (
http://www.theoldpassage.com/) really good food in both.
Of course it's well worth a walk around Lydney, you've the harbour, St.Briavels Castle, Lydney Park Spring GardensDean Forest Railway. If it's really wet then Clearwell caves aren't far (
http://www.clearwellcaves.com/), Littledean Jail and Cinderford isn't a bad small town to visit
Chepstow, with its castle, few shops, it's ok
Plenty of places in the Forest of Dean to photograph. Have a look at
http://www.davidtinsleyphotography.com/ and
http://www.colinrobertsphotos.uk
There's the forest of dean sculpture trail (
https://www.forestofdean-sculpture.org.uk/) that starts from the visitors centre. About 3.5 miles long walk through the forest.
If you do walk the Symonds yat river walk to the footbridge it looks like:
http://www.colinrobertsphotos.uk/the-forest-of-dean/hcpzg1odhvzlozqwkrca5ve8lyk8jy
Theres a steep climbing path up the to peregrine falcon view from there. Might be slippery this time of year?
Hope thats something to help.