bunker

Hi guys, After A LOT of research me and my friend found a way in to the infamous London Road tunnels (WW2 tunnels backfilled about 79 years ago that housed up to 4,000 people in in the war) They are deep in the cliffs of Portsdown Hill and we were wondering if there are any of you guys out...

Found this bunker/storage area looking thing near where i live and i have no idea what it is or what it contains. I thought I would be best to come here before going there in person. Thanks in advance Link to google maps