Bluebell Hill is a lower valley viewing spot sitting beneath the main Bwlch flight line. From the nearby lay-by there is straightforward parking, followed by a short but steep descent into dense wooded hillside below the run.
Once in position, you are looking up into the main transit line as jets cross overhead. Rather than looking down on aircraft, you are below them — giving a strong sense of scale and speed that topside viewing cannot replicate.