If you have ever driven along the M40 between London and Oxford you will have seen the Stokenchurch BT Tower (unless it is in the cloud which it often is - Oxfordshire's answer to the Shard). It stands at the top of the Chilterns escarpment and can be seen for very many miles around. It is a telecommunications tower built of reinforced concrete in 1963. The Tower is just under 100m tall and the top is at 340m above sea level. It has four platforms that hold microwave transmission drums and other antennae. The advantage of microwaves is that they have a huge bandwidth, the disadvantage is that they are limited to line of sight propagation, which is why this tower is so tall and so prominent. It is being made obsolete by the optical fibre network.