After hearing about this place being open, I jumped on the bandwagon so hard I am still picking bits of it from the soles of my boots.
I had hoped to visit with @Grom but word was out that the council were getting it sealed again so he went during the day so he didn't miss his chance, luckily it was still open when I went. After a long day at work I pretended to sleep for a couple of hours before setting off arriving about 2am. I had the place to myself for a couple of hours which was nice considering how many people went in such a short space of time! Sounds like it was a wild party there too!
Some history:
During 1937, with the threat of war imminent, an exchange of letters between the Admiralty, Air Ministry and the War Office resulted in a policy for the provision of protected accommodation at the four main naval ports at Plymouth, Portsmouth, Chatham and Rosyth. It was decided that it would not be practicable or desirable to re-locate the Military HQ's to the coast so a small military liaison staff was allotted to each of the proposed HQ's which the Admiralty and Air Ministry now proceeded to plan and build.
The protection against air attack was particularly pertinent for the Navy at Chatham. During the later stages of WW1 on the night of 3rd September 1917, when 900 men were sleeping in the drill shed at the barracks of HMS Pembroke, 4 German Gotha bombers carried out the first night air raid on the UK. One of the planes dropped two 50 kg bombs through the glass roof of the drill shed killing 130 with 88 seriously injured. It was the largest single loss of life due to air raids in WW1. Large underground shelters were dug into the wall of the barracks before WW2 began.
Thanks for looking!
I had hoped to visit with @Grom but word was out that the council were getting it sealed again so he went during the day so he didn't miss his chance, luckily it was still open when I went. After a long day at work I pretended to sleep for a couple of hours before setting off arriving about 2am. I had the place to myself for a couple of hours which was nice considering how many people went in such a short space of time! Sounds like it was a wild party there too!

Some history:
During 1937, with the threat of war imminent, an exchange of letters between the Admiralty, Air Ministry and the War Office resulted in a policy for the provision of protected accommodation at the four main naval ports at Plymouth, Portsmouth, Chatham and Rosyth. It was decided that it would not be practicable or desirable to re-locate the Military HQ's to the coast so a small military liaison staff was allotted to each of the proposed HQ's which the Admiralty and Air Ministry now proceeded to plan and build.
The protection against air attack was particularly pertinent for the Navy at Chatham. During the later stages of WW1 on the night of 3rd September 1917, when 900 men were sleeping in the drill shed at the barracks of HMS Pembroke, 4 German Gotha bombers carried out the first night air raid on the UK. One of the planes dropped two 50 kg bombs through the glass roof of the drill shed killing 130 with 88 seriously injured. It was the largest single loss of life due to air raids in WW1. Large underground shelters were dug into the wall of the barracks before WW2 began.
Thanks for looking!