Cornwall on Wikipedia.

Altarnun, St. Nonna. Wesleyan Chapel. Both © Bill Henderson.

Biscovey, St. Mary the Virgin. SX 058 536. The former Ebenezer Bible Christian Chapel, built in 1842, and now a sports and social club, sits in a lane opposite Biscovey Road. SX 058 535. Both © Andrew Ross.
Blisland, St. Budocus. From an old postcard in Reg Dosell's Collection - note that the card has been rather heavily processed - the original is very faded. Link.
Bodmin.
Boscastle, St. Symphorian at Forrabury. © Roger Heap. An old postcard view from Dave Westrap's Collection. 190 SX 095 909. Link1. Link2.
Breage, St. Breaca. The font. Interior view. A remarkable wall-painting. All © Carole Sarvis. Link1. Link2.

Caerhays, St. Michael.  © Bill McKenzie. Link.
Carbis Bay, Methodist Church. SW 527 383. © Bill Henderson.
Cawsand, St. Andrew. Congregational Church. Another view. All © James Murray.
Come-to-Good, thatched Quaker Chapel. SW 813 403. © Derek Jordan. Photo is on an external web-site.
Constantine Bay, the ruins of St. Constantine's Church. From an old postcard (franked 1911), Bulman Collection. Link.
Crantock, St. Carantoc, from an old postcard in Steve Bulman's Collection. Two interior views, the Lady Chapel, and the font, both from Christopher Skottowe's Collection.
Cury, St. Corantine. © Bill McKenzie. Link.

Daymer Bay, St. Enodoc. This church has been buried beneath the sands in the past, so much so that the vicar is said to have had to enter the church via the skylight. © Charles Winpenny at http://www.cornwallcam.co.uk/. Anecdote courtesy of Rodney Hall. Another view. © Derek Jordan. Photo is on an external web-site. And a photo from Peter Wood.
Drakewalls, Cemetery Chapel. SX 425 705. © Andrew Ross.

Egloskerry, St. Keri and St. Petroc. From an old postcard in Reg Dosell's Collection.

Falmouth.
Fowey.

Gorran Haven, St. Just. From an old postcard, Geoff Watt's Collection. Link.
Gulval, St. Gudwal. From an old postcard (franked 1905), Bulman Collection. Link. Methodist Church. © David Gallimore.
Gunnislake.
Gwennap, St. Wenappa. © Carole Sarvis. Link.
Gwinear, St. Gwinear. Another view. Both © Carole Sarvis. Link.

Hasletown, Hellesveor Methodist Church. SW 502 398. © Bill Henderson (2009).
Hayle, St. Elwyn. SW 559 375. St. Joseph (R.C.). SW 562 378. Both © Andrew Ross.
Helland, St. Helena. SX 074 710. Methodist Church. SX 073 711. Both © Bill Henderson (2009).
Helston, St. Michael. From an old postcard, Geoff Watt's Collection. Link.

Kenwyn, St. Kenwyn. From an old postcard (franked 1913 or 1918), Geoff Watt's Collection. Link.
Kilkhampton, St. James. From an old postcard, Geoff Watt's Collection. Link.

Ladock, St. Ladoca. SW 894 510. © Bill Henderson. Link.
Landewednack, St. Lanty or St. Winwallow. From an old postcard, Geoff Watt's Collection. Link.
Landrake, St. Michael. And an old postcard view, from Reg Dosell's Collection. Former Methodist Chapel (and adjoining school), now both private residences. The new Methodist Church. Interior view. All except the postcard © James Murray.
Landulph, St. Leonard and St. Dilph. From an old postcard, Bulman Collection. Link.
Lanhydrock, St. Hydrock. © Derek Jordan. Photo is on an external web-site. Link.
Lanssalos, St. Ildierna. Link to external web-site.
Lanteglos-by-Fowey, Cornwall, St. Wyllow. Another view. Previously in the "Unknown" section, these photos were rescued from destruction by Ian Lewis, and identified by Janet Gimber.
Launceston, St. Mary Magdalene. From an old postcard, Bulman Collection.
Liskeard.
Little Petherick, St. Petroc Minor. SW 918 721. © Bill Henderson (2009). Link.
Looe.
Lostwithiel.

Marazion, All Saints. © Mark Summers. Another view, and the chancel, both © Gene Hawkins. Link. Society of Friends. © Rob Brettle.
Mawgan-in-Meneage, St. Mawgan. © Charles Winpenny at http://www.cornwallcam.co.uk/.
Millbrook, All Saints. Methodist Church, formerly Wesleyan, dating from 1873. Link. Cemetery Chapel. All © James Murray.
Mithian, St. Peter. SW 746 471. © Bill Henderson (2009).
Morwenstow, St. Morwenna and St. John the Baptist. SS 205 153. © Nick Hopton. Link.
Mousehole, Wesleyan Church. SW 468 261. © Andrew Ross.
Mullion, St. Mellanus. From an old postcard, Bulman Collection. Link.
Mylor Harbour, St. Mylor. Another view. Interior view. All © Carole Sarvis.

Newlyn.
Newquay.

Par.
Paul, St. Pol de Leon. SW 464 271. © Andrew Ross. Another view. © Bill Henderson (2009). Link1. Link2.
Penzance.
Perranuthnoe, St. Michael and St. Pirran. © Carole Sarvis. Link.
Phillack, the Parish Church. SW 565 384. © Andrew Ross.
Port Isaac, St. Peter (1884). SW 996 809. © Bill Henderson (2009).
Porthilly, St. Michael. © Roger Heap.

Rame, St. Germanus. Another view. Interior view. All © James Murray.
Redruth, dedicated to St. Euny. © Charles Winpenny at http://www.cornwallcam.co.uk/.
Roche, St. Gomonda of the Rock. Of ancient foundation, but now largely of the re-building of 1822. SW 987 587. © Bill Henderson (2009).

St. Anthony-in-Meneage. © Charles Winpenny at http://www.cornwallcam.co.uk/.
St. Blazey, St. Blaize. SX 068 548. United Free Methodist Church (now flats). SX 069 546. Both © Andrew Ross.
St. Blazey Gate, Leek Seed Methodist Church at Doubletrees, built 1824, restored 1903. Another view. SX 060 537. Both © Andrew Ross.
St. Buryan, St. Buryan. SW 409 256. © Bill Henderson (2009). Link.
St. Endellion, the Collegiate Church of St. Endellion, variously St. Endelienta. Another view. SW 996 786. Both © Roger Heap. Another view © Bill Henderson (2009). Link.
St. Erney, St. Erney. © James Murray. Link.
St. Germans, St. Germanus, and the churchyard gate. SX 360 573. Both © Andrew Ross. Another view. From an old postcard (franked 1907), Steve Bulman's Collection. Link1. Link2. Methodist Church, dating from 1903. © James Murray.
St. Germoe, dedicated to St. Germoe. From an old postcard in Steve Bulman's Collection.
St. Issey, St. Issey. SW 928 718. © Bill Henderson (2009).
St. Ives.
St. John, St. John in Cornwall. © James Murray (2010).
St. Just, St. Just. © Bill McKenzie. Former Salvation Army Hall, now a British Legion Club. © Rob Brettle.
St. Just-in-Roseland, St. Justus. From an old postcard in Steve Bulman's Collection. Link.
St. Keverne, St. Keveran. From an old postcard, Graeme Harvey's Collection. Link.
St. Kew, St. Kewa (interior view). From an old postcard in Christopher Skottowe's Collection. Link.
St. Levan, St. Levan. SW 380 222. © Bill Henderson (2009). Link.
St. Martin-by-Looe, St. Martin. © Andrew Ross.  Link1. Link2.
St. Mawgan, St. Mawgan-in-Pydar. Another view. Both © Roger Heap. And another, and an interior view. Both © Louise Kirby. An old postcard view, from Reg Dosell's Collection.
St. Merryn, dedicated to St. Merryn. SW 886 741. From an old postcard in Reg Dosell's Collection. A modern view. © Bill Henderson (2009).
St. Michael's Mount, from an old engraving in Colin Water's Collection. Link.
St. Newlyn East, St. Newlina. From an old postcard in Christopher Skottowe's Collection. Link.
St. Tudy, St. Tudius. © Derek Jordan. Two views © Roger Heap. 1. 2.
Saltash, St. Stephen. Link. Wesley Methodist Church. Both © James Murray.
Sennen, St. Sennen. From an old postcard, Bulman Collection. A modern view. © Bill McKenzie. Link.
Sheviock, The Blessed Virgin Mary. Interior view. Both © James Murray. Link.
Stratton, St. Andrew. From an old postcard in Reg Dosell's Collection. Link.

Tintagel, St. Merteriane. From an old postcard, Steve Bulman's Collection. Link.
Trebetherick, St. Enodoc. © Roger Heap.
Tregonetha, former Chapel, now a private residence (can you provide a denomination?). SW 956 638. © Bill Henderson.
Tregrehan, Methodist Chapel. A former Primitive Methodist Chapel, now a home. Both at SX 044 537, on opposite sides of the road. Appreciative thanks to the home owner for his permission to photograph the former chapel. Both © Andrew Ross.
Trevone, St. Saviour. © Bill McKenzie. Link.
Truro.
Tywardreath, St. Andrew the Apostle. SX 085 541. Link. Methodist Church, on Church St. SX 084 542. Both © Andrew Ross.

Veryan, St. Symphorian. © Derek Jordan. Link.

Week St. Mary, St. Mary the Virgin. SX 237 977. © Les Horn (2009). Link.
Wendron, dedicated to St. Wendron, St. Gwendron, or St. Wendrona. SW 678 311. © Steve Taylor. Link1. Link2.

Zennor, St. Senara. © Bill McKenzie. Link.