Tewin is set in a superb rural landscape which retains many features characteristic of ancient countryside and which supports a rich variety of wildlife. The village contains areas set aside for the Hertfordshire and Middlesex Wildlife Trust which are carefully managed by volunteers.
Tewin grew up around the river Mimram, which still flows through Tewin. This fed by many springs in Tewin, and is a rare chalk stream. This river, and the wildlife it supports is under threat from water extraction - see the Friends of the River Mimram Facebook page and The Mimram on Walsworthblog for more information.
Tewin borders Panshanger Park, this is gradually being opened to the public. You can now walk the Oak Trail, and see the Broadwater, the Great Oak, the Orangery and the location of Panshanger House, with its views across the Repton historic landscape. - see The Friends of Panshanger Park website for more information.