River Lune Bridge (built as rail but now carries a road), Lune Millennium Bridge (pedestrian and cycle) and Carlisle Bridge (carrying the West Coast Main Line railway, and with a public walkway on the eastern side) which is the furthest downstream of the bridges. This part of the Lune is also the site of the old Port of Lancaster, probably a port from Roman times; the Lancaster Port Commission was established in 1750 to improve navigation on the estuary. Between 1750 and 1767, St George's Quay and New Quay were built in Lancaster and in 1779 the port facilities were extended closer
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