Iolo Williams explores four historic estates in Wales, finding out what special places they are for wildlife. These parks are now open for everyone to enjoy but sometimes the wildlife goes unnoticed. Iolo meets with people who have inside knowledge to share, uses his expertise as a naturalist to track down wildlife and finds elusive night-time creatures. In this final episode, Iolo is exploring the dramatic Stackpole Estate in Pembrokeshire. Iolo goes underwater in the Bosherston Lily Ponds to try and find pike, has a wonderful time spotting otters in the rain and gets a glimpse into the nightlife of the old estate buildings where a large breeding colony of greater horseshoe bats can be found.