These--if ancient--seem to be invariably on (not merely alongside) a ley, and in many cases are at the crossing of two leys, thus appropriating the sighting point to a new use. A ley often passes through a tump adjacent to the church, and a cross ley through both church and tump. In other cases a mark stone site became the churchyard cross, and a cross ley comes through both church and cross. In many cases one of the leys went through the tower only, and it is possible that tower and steeple were built to be used as sighting points, although on the other hand a large church did in fact block the road. I will make no surmises on these interesting points. The sighting system may have been in decay or the tracks abandoned when the churches were first built on the sighting points. I do not think it probable that leys were made to provide sites for churches.
[paragraph continues] In almost every old town or village will be found examples of a church built on and blocking an ancient road although new roads (as at Weobley) are often made on one or both sides. I show examples of a number. Broad Street blocked by All Saints, Offa Street (a striking example) with St. Peter's Tower dead on one end, and the Cathedral Tower dead on the other end. Other examples: Ledbury, Wigmore, Shrewsbury (Fish Street), Kington, and Madley, where tower, churchyard cross and village cross are on one ley, and tower, nave, chancel, and a mark stone in the village on a lengthwise ley.
At Warwick a chapel is over a town gateway, and in Exeter an ancient lane is also allowed to continue as a tunnel under the altar of a small church, two curious instances of the right of way being continued and the desire of the clergy to use the site also attained. Kenderchurch is a striking instance of a church perched on the apex of a sighting mound, and in other districts I can think of Bren Tor (Dartmoor), Harrow, Churchdown (Gloucester), and the two St. Michael's Mounts, these last obviously terminals of leys, as is St. Tecla's Chapel out in the channel below Chepstow, the termination of the beach ley which gives its name to Beachley Village.
In London St. Paul's blocks the Watling Street and Ludgate Hill leys, and St. Clement Danes, St. Mary le Strand, and St. Martin's in the Fields are all on another ley with subsidiary roads evolved on each side of the churches.