The reserve is managed by the Northmoor Trust who established it in 1982.
Castle Hill is the site of an Iron Age hill fort of which the ditch around the base of the hill is the only obvious sign. In the clump of trees at the top of the hill is the Poem Tree in which Joseph Tubb carved a poem in 1844-45.
In the woodland below, occasionally, Muntjac deer can be seen. There is a hide at the the ponds from where you may be lucky enough to see a Heron or even a Kingfisher.
There are 30 different varieties of butterflies in the reserve and 120 different bird species have been counted.
The reserve is open at all times. A car park is located just off the Little Wittenham to Brightwell-cum-Sotwell road and there is limited parking near the church in Little Wittenham. Guided walks and events are arranged by the Northmoor Trust. Contact them on (01865) 407792 for more information.
While visiting the reserve, also take a walk down to Day's Lock where each year, the International Pooh Sticks Championship is held.