A pylon is a tower-like structure. They can represent steel towers or masts that support antennas for television, radios and cell phones, or electric wires. A pylon can also be the vertical support for a bridge or a tower marking an entrance of some sort. There are several different types of pylons, the oldest of which date back to ancient Egypt.
Large towers made from a network of steel constitute a practical type of pylon. They are easy to maintain, and can be climbed by hand in order to be serviced or modified. Other structures that do not allow climbing must be serviced by cranes or lifts.
A monopole is a single, tall pole with an antenna mounted on the top. Some have ladders on the side, which allows servicemen to climb up for simple operations. Any major modifications must be done by use of a crane.
If a single pole pylon becomes extremely tall, such as between 60 m and 300 m in height, then supporting cables are attached in each direction around the pylon. These super-pylons are generally used for television or cell phone towers.
An antenna can be discreetly mounted on a pylon that is made to look like a flag pole. This is an option for residential areas or other places where an unsightly tower is not desired. Also used in residential areas are pylons that look like fake chimneys or disguised in trees.
Pylons designed to hold electric cables and conductors are constructed on the lattice tower model, with two or three sets of vertical arms to hold the wires. Towers with two arms generally appear near airports where a shorter profile is required.
On a suspension bridge, the pylons are the tall supports that hold up the cables of the bridge. They sink deep into the ground beneath the water, with large concrete foundations. Pylons may also be structures on either side of the bridge, providing a formal entrance.
Pylons in ancient Egypt were large structures that marked the entrance to temples. They were high enough and strong enough to create a defensive barrier. They were also decorated with religious symbols. Symbolically, they represented a division between the holy within the temple and the evil without it.