National Cycle Network: Route 21 Guides and maps of cycle routes along National Cycle Route 21 in East Sussex. Find out how to obtain other East Sussex cycling leaflets, maps and books. Acrobat (PDF) NCR 21 - overview map (large file size) (2298k)An overview map of National Cycle Route 21. This is a large file size, high resolution map. NCR 21 - overview map (smaller file size) (880k)An overview map of National Cycle Route 21. This is a smaller file size, low resolution map. Cuckoo Trail & High Weald Circular (29 miles) (593k)A moderately challenging circular route passing through Burwash and the follies at Brightling, with some hilly sections. Ashdown Forest & Crowborough Circular (29 miles) (681k)A strenuous circular route through Ashdown Forest around the outskirts of Crowborough. Hilly and not for the faint-hearted! Cuckoo Trail & Pevensey Levels Circular (23 miles) (547k)Easy to moderate riding along the Cuckoo Trail and Pevensey Levels, with only a few shorter climbs. Cuckoo Trail & Low Weald Circular (24 miles) (559k)An easy ride mostly along bridleways and quiet lanes, passing through Hellingly and Golden Cross. Forest Way & Ashdown Forest Circular (39 miles) (692k)A moderately strenuous route, with both hilly sections and glorious flat riding along the Forest Way disused railway line.