Teesdale is a superb area for walking, be it an evening stroll, a three or four hour walk or a whole day strenuous hike. Public footpaths are generally well-marked (except over moorland) with stiles and gates kept in good condition and clearly marked. Middleton itself is the centre for the famous Teesdsale Challenge Walk prgramme (http://www.teesdalechallengewalks.net ).
In a folder in the cottage you will find a large array of published walks in the area. On the shelves you will find a copy of 'Walks of Discovery : Upper Teesdale' which outlines 14 walks that start from Middleton. The best walking book for Teesdale as a whole is Paul Hannon's 'Walking County : Teesdale'. This is a small (easy to carry) well-written book with 22 excellent Teesdale walks of between 5 and 8.5 miles (unfortunately currently out of print whilst it is being updated and revised, but there are still some copies available in some walking or book shops - £6.99). His walks 13 (Lunedale), 14 (Huddeshope Beck) and 15 (Teesdale Meadows) can easily be started from the cottage.
In addition there are superb longer moorland walks over Monks Moor to Great Eggleshope and back via Coldberry and Hudeshope Beck (4 hours) and along the Pennine Way past Kirkcarrion to Lunedale, then over Crossthwaite Common to Holwick and back to Middleton along the Tees Valley footpath (10 ½ miles). When walking over moorland in the area do make sure that you have with you a compass and an Ordnance Survey Explorer OL31 or OL19 and that good visibility is expected. Remember that the grouse shooting season runs from August 12th to December 10th (Pheasants from October 1st to February 1st) and that this is an old lead mining area with numerous shafts, some of which can be obscured and yet very deep.
If you are just looking for a stroll from the cottage door such as a circular walk down and around the village there is an excellent network of footpaths in the area, as you can see from the following maps on the Durham County Council web-site (https://durham.gov.uk/definitivemap). There are also useful additional paths such as a path from the junction of the Snaisgill and Stanhope Roads into Hudeshope Wood and the permissive path on the old railway line from Middleton towards Holwick. If you need any advice at all over footpaths or walks please do not hesitate to ask.
Almost all farmers in the area are very friendly and helpful. Please do stick to footpaths, keep dogs on leads in fields or moorland areas where there are livestock and close gates behind you.