Valentine Cottage is in Keswick, up a quiet lane just off the main street. It's a proper stone cottage. The road doesn't get much traffic. You're above the town a bit so you get a good view of the fells from the front.
It sleeps five. Three bedrooms, one bathroom. It's a 4 Star place, so it's well looked after. Everything works, the heating's good, and you won't run out of hot water. The garden is enclosed, which is handy.
You're two minutes from everything. Shops, pubs, places to eat. The Theatre by the Lake is a short walk. Fitz Park is right across the footbridge over the River Greta. The park has a play area, tennis, bowling, and lots of space. The leisure centre is next to it if you want a swim or a gym session.
Derwentwater is about a fifteen minute walk. You can get the launch from there, or just walk around the lake. You can be on the fells in no time.
For facilities, you've got a washing machine, dishwasher, WiFi, and TV. Bedding and towels are included. There's a cot if you need it and space to store bikes. You can bring one dog.
Useful links for planning: Lake District National Park and National Trust Lake District.