Tredegar House Country Park
This striking 17th-century mansion in Newport is surrounded by 90 acres of beautiful gardens and parkland. Highlights include the large lake which has a lovely waterside walking path. There are also three delightful formal gardens - The Orchard Garden, the Cedar Garden and the Orangery Garden.
The Sirhowy Valley Ridgeway Walk starts at Tredegar so you could continue your walk along this lovely waymarked trail towards Machen. If you were to head north from the park on the trail it would take you to the wonderful Fourteen Locks on the Monmouthshire and Brecon Canal. There's nice waterside paths here and an excellent visitor centre with a wealth of information on the area. Also near Newport is the splendid Newport Wetlands nature reserve where there's lots of nice trails and wildlife spotting opportunites.