Long barrows are "Bridge houses" This is my conclusion.
We also have "Elmet" Helmet / Helme. This I believe is the name of the Warriors Tomb. But the Roman Helmet term that has a bridge on top of it, may have replaced the Celtic Helmets association.
If we can apply the term "Bridge Houses" to Long Barrows, then can we use this term for the smaller ones as well?
Not only Bridges, masts, alignments for travel across three dimensional space, between geographical points & places of the outside world, but also a deeper Inner "bridge" to a visionary world, an inner world of Religious experiences? And the Word "bride" to join.. Also has symbology between male & Female & we have the two different style of sites the Long Barrow & round Barrows. Some of the Round Barrows have inside them a standing stone or such Elongation.
I believe the map maker are putting marks but not on the right places on the map. being elusive see also https://ibb.co/Xbkqffs
Further discussion on the matter (caution contains strong language some may find offensive