Peak District National Park
Ok, no Wikipedia this time. Peak District is a large national park located in northern England (just to make it clear, England =/= UK, so northern England is NOT Scotland, look at the middle of the island). Park covers several areas such as Derbyshire, South and West Yorkshire and few more. For this reason, selected pictures for this post do not show everything. Hopefully, they will give you an idea how diverse the region is and whether you would like to visit. Personally, I would recommend it, but some things need to be considered before going. Firstly, it lies close to cities such as Manchaster or Sheffield, so during weekend trails are bit crowded. Also, as the name suggests, it has lot of peaks, but many trails are easy to walk on. So if you like hiking, but do not want to get tired by climbing, you will be fine. Thre are also bicycle routes and bicycle rental shops if you prefer cycling. So, if you like hiking, cycling or just want a break from the city, it's definetly a place to visit and a POI.
Upper Derwent Valley is a large area that includes three large water reservoirs. Ladybower is the easiest one to get to, as you can just drive by car or use bus. To see the other two, Derwent and Howden Reservoir, you need to walk. But to save time and energy, just rent a bicycle. The route around those reservoirs is really long, but is flat and so, perfect for cycling.
Castleton is a small and quiet town located in Peak District. It is known for caves and ruins of an castle (only keep and some remains of walls is left ), both of them you can visit after paying a fee.
Chatsworth is a large estate and the seat of the Duke of Devonshire. You can enter the house (for a fee) and see the interior and a collection of paintings, furniture and many other artefacts. However, I wouldn't recommend that, since it looks more like a warehouse with everything just thrown in. On the other hand, the gardens around the house, Chatsworth town and park are much better option. One last thing, the house was one of the filming locations in the film 'Pride and Prejudice' (2005), The Dutchess (2008) and other less known productions.
Near Loxely, just on the edge of the park. It's quite populated, so if you are looking for quietness, you need to walk or drive deeper into Peak District. However, unlike Ladybower and other reservoirs mentioned above, you can sail here if you have a boat.
Matlock is a small town located south east of the park. Not much is there to see, only a small church and few farmhouses. There is a large mansion on a hill which is visible from town. DON'T GO THERE, it's off limits and with high fence around it. Apart from that, Matlock is pretty much a starting point for hiking trips into the Peak District.
OK, this is it. Those areas are the ones I have visited, but there is many more, so if I have chance and time I will go there and update this post. I may add some more pictures here as well, I didn't developed everything I have (or you can google those locations and see others' pictures and get more information). If you have any questions, let me know in comment below.