River Lune the West Coast Main Railway Line run. Below the gorge, the valley broadens out into Lonsdale. Bridges over the Lune include the Devil's Bridge near Kirkby Lonsdale and the Lune Millennium Bridge in Lancaster. At Caton, about upstream from Lancaster, there is a cluster of three bridges (one stone road bridge and two disused iron rail bridges now used as foot/cyclepaths) at the "Crook o' Lune". Here in a 180-degree right-hand bend the Lune turns back on itself; this is followed by a 90-degree left-hand bend forming the shape of a shepherd's crook and creating a beauty spot which was
Spherical lune two polar opposite points. Common examples of great circles are lines of longitude ("meridians") on a sphere, which meet at the north and south poles. A spherical lune has two planes of symmetry. It can be bisected into two lunes of half the angle, or it can be bisected by an equatorial line into two right spherical triangles. The surface area of a spherical lune is 2θ "R", where "R" is the radius of the sphere and θ is the dihedral angle in radians between the two half great circles. When this angle equals 2π radians (360°) — i.e., when