For a small market town to have one museum is unusual – to have two, as Northleach does, is remarkable. One, the Cotswolds Discovery Centre, is closely associated with its surroundings. The other, Keith Harding's World of Mechanical Music, is one of those eccentricities that has, by happenstance, ended up here in Northleach.Mechanical music museumThe World of Mechanical Music is in the High Street at Oak House, a former wool house, pub and school. There are daily demonstrations of all manner of mechanical musical instruments, as well as musical boxes, clocks and automata. Some of the instruments, early examples of 'canned' music, date back more than 200 years. The presentation is simultaneously erudite and light-hearted. (You may also listen to early live recordings of concerts given by some of the great composers, including Gershwin and Grieg.) This is something more than a museum – both serious historical research and highly accomplished repairs are carried out here.House of correctionTo the west of the town centre, at a corner of a Fosse Way crossroads, lies the Cotswolds Discovery Centre. It is housed in an 18th-century prison, or 'house of correction', built by the prison reformer and wealthy philanthropist Sir Onesipherous Paul. He was a descendant of a family of successful clothiers from Woodchester, near Stroud, who were also responsible for the construction of what is now the Prince of Wales's house at Highgrove. Paul's intentions were surely good, but conditions in the prison were still harsh and the treadmill was still considered effective as the unrelenting instrument of slow punishment. As well as a restored 18th-century cell block, you'll find the Lloyd Baker Rural Life Collection, an interesting collection of agricultural implements and machinery which displays fascinating photographs showing what rural life in the Cotswolds was once like.Then and nowNorthleach itself, like Cirencester and Chipping Campden, was one of the key medieval wool trading centres of the Cotswolds. Though it once stood on a crossroads of the A40 and the Fosse Way, neither route now passes through the town, the completion of the A40 bypass in the mid-1980s leaving the town centre a quiet and very attractive place to visit.The main street is lined with houses, some half-timbered, dating from the 16th to the 19th centuries. Many of these retain their ancient 'burgage' rear plots that would have served as market gardens. Above the market square is a tiny maze of narrow lanes, overlooked by the Church of St Peter and St Paul, the town's impressive 15th-century Perpendicular 'wool church'.

From Northleach Market Place, with the church behind you, turn left and walk along the main street to the traffic lights at the A429. Cross with care, keep left of the Cotswolds Discovery Centre (the Old Prison), and immediately after passing the museum turn right through a gate into a field. Go half right to cross a stream by a field corner and into the next field.

Aiming for a church tower, go diagonally right up the field to a gate. Pass through this into the next field and, keeping fairly close to the field's right-hand margin, head for a kissing gate on the far side. Pass into the next field and walk around the right-hand perimeter in the general direction of Hampnett Church. This will bring you to a kissing gate at a road.

Turn left and almost immediately come to a concrete track on your left. To visit the church walk ahead and then return to this track. Otherwise, turn left down the track and follow it as it descends to pass farm buildings. Follow the track right then left, up towards a gate. Go through it and continue to follow the track, eventually striking a road. Cross this to walk along another track (Monarch's Way) all the way to another road by a reservoir.

At this road turn left and walk until you reach the A429. Cross with great care to a gap in the hedge at a marker post, then walk along a grassy track until you come to a farmyard. Walk through the yard and out the other side along a track to another road.

Cross to a track and follow this for about 330yds (300m). Turn left through a gate to enter a field and follow the left margin with a stone wall to your left. Northleach is ahead of you. Where the field comes to an end, go through a kissing gate and go straight down the field to a kissing gate beside a playground.

Go through and, bearing right, walk the length of the tennis court on your left to cross a stream. Walk the length of an alley and, at the top, turn left to return to the starting point.