BAAG 'Post Y', Chek Keng [????- ]
Post Y was an important site in WW2, and still stands today.
A BAAG post was set up at Chekeng Village - Post Y; which was also a HQ of the [Communist 'East River Brigade'] Guerrillas. The BAAG Advance HQ at Wai Chow (Huizhou) sent agents to HK through Post X (Shayuchung of Dapeng Bay), by guerrilla-operated junk to Post-Y (Chekeng) and throught the Ancient Route to urban Kowloon, one of the Safe House (Post-Z) being the Kwong Hang Store at Portland Street, Shamshuipo, which was operated by the Red Guerrillas.
If you ever hike down to the village of Chik Kang [Chek Keng] on Long Harbour you will see the BAAG forward post, [ie Post Y] still intact. You can see two photos of it on p. 211 of Volume IV of the BAAG Series, which you will find in Special Collections, HKU Library. You will find information about Post 'Y' in Edwin Ride's book 'BAAG, Hongkong Resistance', p. 215-6, also in Special Collections.
Contact the caretaker if you can - he is a most interesting character.
Thanks to Kent Shum for providing the exact location. I've waked past here several times on the way out from Tai Long Wan without ever realising it's significance. I'll have to take a closer look next time