Berberis Lodge is on Mercia Marina in Willington. It's a holiday lodge, so it's modern. It feels quite private, but you're still right on the marina.
It sleeps four. Two bedrooms, both with their own bathrooms, which is handy. You can have the second bedroom as a super king bed or as twins. The stairs to the veranda are only a few steps. There's outdoor seating out there overlooking the lake.
Inside it's open plan. Everything you'd expect is there: a dishwasher, a washer/dryer in a cupboard, WiFi. It's got a 4 Star rating, so it's comfortable and well-equipped.
The marina itself has places to eat and a few shops. You can borrow bicycles here for free to go along the trails. Boat tours sometimes run from the marina too. It's a good base for walking or cycling along the canals.
You're about half an hour's drive from the southern Peak District. Places like Bakewell and Ashbourne are easy to get to. Closer by, you've got Calke Abbey and Kedleston Hall. Chatsworth is about 40 minutes away.
For a short drive, Burton-upon-Trent has the National Brewery Museum. The National Memorial Arboretum is near Lichfield. Alton Towers is about half an hour away, if that's your sort of thing.
Facilities: all the bedding and towels are included. There's parking right by the lodge. One well-behaved dog is welcome.
Useful links for planning: National Trust Peak District and Peak District National Park.