Best estimates suggest that there are around 300 disused railway tunnels in the UK - some of them are extraordinary structures. Below is a list of 48 which are over 1,000 yards in length. The longest exceeds 3 miles.

We don't claim that it's definitive - if you know of one we've missed (or you can provide a missing date or picture), please drop us an email.

The known status of the two portals is given in brackets alongside the bore type, with the south/west portal described first. The key is given below:
fenced fence (full/partial) with no gate gate fenced (full/part) with gate
wall partial height wall door full height wall with door/gate
bricked full weight wall buried portal lost beneath infill
open portal open obstructed portal open but partly obstructed
flooded portal open but liable to flood collapsed portal partly collasped
The 'Info' entry goes to a story, gallery or external website (highlighted in red) giving more information or pictures of that tunnel. By clicking on a red 'Location' name, you'll be taken to an OS map showing where to find it.
Woodhead (New) 5,346 yds
Opened 1954 Company British Rail
Closed 1981 Bore Double (gate/gate)
Location Dunford Bridge, South Yorks
Info Gallery
Standedge (Up & Down South) 5,342 yds
Opened U1870 Company London & North Western
D1849 Bore Singles (gate/gate)
Closed 1968 Location Marsden, West Yorkshire
Info
Woodhead (Up & Down Old) 5,302 yds
Opened U1852 Company Great Central
D1845 Bore Singles (gate/gate)
Closed 1954 Location Dunford Bridge, South Yorks
Info Gallery
Rhondda 3,443 yds
Opened 1890 Company Rhondda & Swansea Bay
Closed 1962 Bore Single (buried/buried)
Location nr Treherbert, Sth Wales
Info Single photo
Catesby 2,997 yds
Opened 1897 Company Great Central
Closed 1966 Bore Double (gate/gate)
Location nr Daventry, Northants
Info Warwickshire Railways
Victoria 2,706 yds
Opened 1849 Company London & North Western
Closed 1972 Bore Double (obstructed/open)
Location Liverpool
Info 28 Days Later
Bolsover 2,625 yds
Opened 1897 Company Great Central
Closed 1951 Bore Double (buried/unknown)
Location Bolsover, Derbyshire
Info
Queensbury 2,501 yds
Opened 1878 Company Great Northern
Closed 1956 Bore Double (flooded/door)
Location Queensbury, West Yorks
Info Gallery
Merthyr (Aberdare) 2,497 yds
Opened 1853 Company Vale of Neath
Closed 1967 Bore Single (wall/gate)
Location Merthyr Tydfil, Sth Wales
Info Cardiff Rail
Gildersome 2,331 yds
Opened 1904 Company London & North Western
Closed 1966 Bore Double (buried/door)
Location nr Morley, West Yorks
Info Gallery
Drewton 2,114 yds
Opened 1885 Company Hull & Barnsley
Closed 1958 Bore Double (obstructed/fence)
Location nr South Cave, East Yorks
Info Gallery
Wapping 2,111 yds
Opened 1830 Company London & North Western
Closed 1972 Bore Double (unknown/unknown)
Location Liverpool
Info Old Liverpool Railways
Wenvoe 1,868 yds
Opened 1886 Company Barry Dock & Railway
Closed 1964 Bore Double (open/gate)
Location nr Cardiff
Info Cardiff Rail
Combe Down 1,825 yds
Opened 1854 Company Somerset & Dorset
Closed 1966 Bore Single (door/door)
Location Bath
Info After Closure: The Somerset & Dorset
Glenfield 1,786 yds
Opened 1832 Company Leicester & Swanington
Closed 1966 Bore Single (door/buried)
Location nr Leicester
Info Single photo
Harecastle South 1,766 yds
Opened 1848 Company North Staffordshire
Closed 1965 Bore Double (unknown/unknown)
Location nr Kidsgrove, Staffs
Info 28 Days Later
Burdale 1,746 yds
Opened 1853 Company North Eastern
Closed 1958 Bore Single (door/door)
Location nr Malton, North Yorks
Info Gallery
Sandsend 1,652 yds
Opened 1883 Company North Eastern
Closed 1958 Bore Single (wall/door)
Location Sandsend, North Yorks
Info Flickr
Ramsgate 1,638 yds
Opened 1863 Company South Eastern & Chatham
Closed Bore Double (door/unknown)
Location
Info 28 Days Later
Cymer 1,591 yds
Opened 1866 Company Great Western
Closed 1970 Bore Single (bricked/buried)
Location nr Maesteg, Sth Wales
Info
Colwall Old 1,567 yds
Opened 1860 Company Great Western
Closed 1926 Bore Single (unknown/unknown)
Location nr Great Malvern
Info
Lees Moor 1,533 yds
Opened 1878 Company Great Northern
Closed 1963 Bore Double (gate/wall)
Location nr Keighley, West Yorks
Info One-shot gallery
Thackley (Old South) 1,496 yds
Opened 1845 Company Midland
Closed 1968 Bore Single (gate/gate)
Location nr Shipley, West Yorks
Info 28 Days Later
Lydgate 1,335 yds
Opened 1856 Company London & North Western
Closed 1955 Bore Double (door/bricked)
Location nr Oldham, Gtr Manchester
Info Flickr
Graig (Treforest/Pontypridd) 1,323 yds
Opened 1888 Company Barry
Closed Bore Double (bricked/bricked)
Location Pontypridd, Sth Wales
Info Disused Stations
Ventnor 1,313 yds
Opened 1866 Company Isle of Wight
Closed 1966 Bore Single (gate/gate?)
Location nr Ventnor, Isle of Wight
Info Isle of Wight Nostalgia
London Road 1,300 yds
Opened Company Caledonian
Closed Bore Double (unknown/unknown)
Location Glasgow
Info Flickr
Clifton Hall 1,298 yds
Opened 1850 Company London & North Western
Closed 1953 Bore Double (buried/buried)
Location Pendlebury, Gtr Manchester
Info Wikipedia
Barnsdale 1,226 yds
Opened 1885 Company Hull & Barnsley
Closed 1959 Bore Double (open/open)
Location nr South Elmsall, Sth Yorks
Info
Ballingham 1,208 yds
Opened 1855 Company Great Western
Closed 1964 Bore Single (open/open)
Location nr Hereford
Info Cardiff Rail
Whitrope 1,208 yds
Opened 1862 Company North British
Closed 1962 Bore Double (gate/gate)
Location nr Newcastleton, Scottish Borders
Info One-shot gallery
Mansfield Road 1,200 yds
Opened 1897? Company Great Central
Closed Bore Double (unknown/buried)
Location Nottingham
Info Wikipedia
Tidenham 1,190 yds
Opened 1876 Company Great Western
Closed 1981 Bore Single (open/open)
Location nr Chepstow, Monmouthshire
Info Cardiff Rail
Pinnock 1,173 yds
Opened 1874 Company Great Western
Closed 1968 Bore Double (open/open)
Location nr Fowey, Cornwall
Info
Mapperley 1,132 yds
Opened 1876 Company Great Northern
Closed 1960 Bore Double (unknown/open)
Location nr Nottingham
Info 28 Days Later
Gyfylchi (Tonmawr) 1,124 yds
Opened 1883? Company South Wales Mineral
Closed Bore Single (bricked/collapsed)
Location nr Maesteg
Info 28 Days Later
Bullo 1,064 yds
Opened Company Great Western
Closed Bore Single (wall/wall)
Location nr Cinderford, Gloucs
Info Cardiff Rail (single photo)
Haddon 1,058 yds
Opened 1863 Company Midland
Closed 1967 Bore Double (bricked/unknown)
Location nr Bakewell, Derbyshire
Info Wikipedia
Privett 1,058 yds
Opened 1903 Company London & South Western
Closed 1968 Bore Double (door/bricked)
Location nr Peterfield, Hampshire
Info Wikipedia
Clayton 1,057 yds
Opened 1878 Company Great Northern
Closed 1963 Bore Double (door/buried)
Location nr Bradford, West Yorkshire
Info Gallery
Scotland Street 1,052 yds
Opened 1847 Company Edinburgh, Leith & Newhaven
Closed 1925 Bore Double (door/unknown)
Location Edinburgh
Info Subterranea Britannica