Apart from Southend itself, it is the largest town in the Rochford Hundred.
The wooded Rayleigh Mount, now in the hands of the National Trust, is the site of the motte and bailey castle constructed by Sweyn of Essex in the 11th century.
One of the town's major landmarks is the restored Rayleigh Mill, built in 1809.
Holy Trinity Church, at the top of the busy High Street, has an excellent 15th century tower and a Tudor brick porch.
The Martyrs Memorial, an obelisk in the High Street, commemorates Protestants burned at the stake at Rayleigh in Queen Mary's bloody eign, and also two local men who met a similar fate at Smithfield in London.
The "leigh" suffix signifies a clearing in the forest which once covered most of Essex. There are still many acres of woods nearby.
Blue Badge Guide Colin Crosby is available to lead Guided Walks around Rayleigh for groups.