If you feel the need to demarcate your property with an intruder-proof barrier, there are several styles of security fencing to do the job. Aesthetics are not the first priority in this situation, though there are some styles that look good and keep people out.
Chain Link Fence
Security is the singular purpose of this type of steel mesh fencing. Stout posts set deeply in concrete and wire fencing that is difficult to cut through or climb over make it the standard around the world. Optional extensions slide onto the top of the posts to support barbed wire if you need to let criminals you are serious about keeping them out.
Chain link fencing is as stark as can be, but there are optional plastic slats that slide into the mesh to create a visual barrier and soften the appearance a bit. Besides the typical galvanized grey metal style, there are colored options that also help to make it seem less austere.
Home Depot has a great selection of chain link fencing products, including all the necessary hardware, as well as slats in green, beige, reddish-brown and black, along with rolls of fencing in green and black. Virtually all of Home Depot's fencing products were rated with 4 or 5 stars by customers.
Less common, but just as effective as chain link fence outfitted with barbed wire, palisade fencing consists of vertical steel posts with a pointed tip that are nearly impossible to climb over. It is more expensive than chain link, but it can be quite attractive.
Ornate wrought iron fences can be built in this style, bridging the gap between fortitude and elegance. Like chain link fencing, installation requires the skills and tools of a specialist.
Hiring a specialized fence contractor to build a custom palisade fence to surround your property is an expensive proposition, but there is at least one company out there that makes a modular palisade fence that is a feasible DIY project; the company is called Freedom and their fences are available at Lowes.
Wood Privacy Fencing
6-foot fencing with a solid wood facade is a very attractive way to enclose your property and can be a type of security fence if designed appropriately. The key is to use a style of wood fencing with vertical boards, rather than horizontal pieces, which can facilitate climbing. Also, design the fence so that it extends all the way to the ground - you don't want people to be able to shimmy underneath.
The standard 6-foot privacy fences aren't terribly difficult for a determined criminal to climb over, so you might want to consider adding a 2-foot extension in the form of decorative lattice panels as an added deterrent.
Home Depot offers an impressive selection of prefabricated wood fence panels in a variety of styles, including lattice extensions, most of which have received very high marks in customer reviews.
Wire Mesh Fencing
Though it is not typically intended as security fencing, woven wire fencing can be an effective deterrent if is at least 5 feet tall. The downside is the wire is easier to cut through than chain link; on the other hand, wire mesh fencing is cheaper and easier to install than any other type of security fence.
It is important to use the versions that have small holes (2 inches or less) that make it difficult for someone to get a shoe into if they are trying to climb over.
Suppliers that specialize in rural lifestyles, such as Tractor Supply Company, are the best place to look for wire mesh fencing. Tractor Supply offers 100-foot rolls of 60-inch tall horse fencing for the impressively low price of $170 - definitely the cheapest option for security fencing out there.
A Simple Alternative
A strand of electric fence wire can transform any fence into a security fence. The high-voltage systems used to protect commercial properties aren't suitable for home use, but the type that is used for horse pastures also gives enough of a jolt to deter a criminal - though no physical harm is caused to humans (or animals) with this type of electric current. If you decide to go this route, check with your municipality to make sure using electric fencing is legal before you install it.
Peace of Mind
A security fence is a major investment, but will certainly help you to sleep better at night if you feel criminal activity is a threat in your neighborhood. The most affordable versions are generally not very aesthetic, but you can always add a dense hedge on one or both sides of the fence to make it disappear over time.