A few stars who supposedly had Playboy mansion tunnels running to their homes: J. Nicholson, W. Beatty, K. Douglas and J. Caan

Along the same lines, Merv Griffin's estate is supposedly the meeting place for the Bohemian Board each year to decide on the "festivities" according to CDAN:

"Not even a mile from the famed music festival(Coachella) in the desert are two separate compounds. One is the famed home of a long time entertainer who was A+ list and continues to make tons of money even after death from the empire he established(Merv Griffin). One of the men he groomed is someone all of you know (Ryan Seacrest). There is a gap between the entertainer's estate and a subdivision that will never be zoned for construction. It is referred to in the compound as the gap. If this was Cold War East Berlin it would probably be called the death zone. This gap is the length of a football field and runs around the compound much the same way a moat would. High walls prevent anyone from just walking into the gap. For much of the year, it is just a place that, if you have enough money, people can rent out. It is very expensive to rent and no matter how much you pay, one of the homes is completely off limits. That home is the nerve center of the board of The Bohemian Grove who use the desert compound each Easter to work out the final details for their summer ritual. They also are known to try out various males and should things get a little rough or one of those males would like to run off during the night, the gap stops them cold. Nothing gets past the gap. The nerve center has lists of members and files on each and dirt on each. It has countless servers filled with all kinds of information about all kinds of people.

Now, one added little tidbit to this. I mentioned two compounds. There is a tunnel between the entertainer compound and also a compound consisting of three homes built by a shell company of the company that is a huge part of the music festival. The three homes and the entertainer compound are probably a good half mile apart, maybe a touch more, but there is a fully lit cement tunnel much like you would see underneath a football stadium that runs between the two locations. It can easily fit several golf carts or small cars in the passageway. Escape route for performers or a way for them to enjoy something more ominous courtesy of the Bohemian Grove board."

not sure if BG board still meets there after it was sold to Mark Majerovic, who for $7 million in 2013

If you want to see "the gap", the address of the Griffin estate is 81345 Avenue 54, La Quinta, CA 92253

A few stars who supposedly had Playboy mansion tunnels running to their homes: J. Nicholson, W. Beatty, K. Douglas and J. Caan

Along the same lines, Merv Griffin's estate is supposedly the meeting place for the Bohemian Board each year to decide on the "festivities" according to CDAN:

"Not even a mile from the famed music festival(Coachella) in the desert are two separate compounds. One is the famed home of a long time entertainer who was A+ list and continues to make tons of money even after death from the empire he established(Merv Griffin). One of the men he groomed is someone all of you know (Ryan Seacrest). There is a gap between the entertainer's estate and a subdivision that will never be zoned for construction. It is referred to in the compound as the gap. If this was Cold War East Berlin it would probably be called the death zone. This gap is the length of a football field and runs around the compound much the same way a moat would. High walls prevent anyone from just walking into the gap. For much of the year, it is just a place that, if you have enough money, people can rent out. It is very expensive to rent and no matter how much you pay, one of the homes is completely off limits. That home is the nerve center of the board of The Bohemian Grove who use the desert compound each Easter to work out the final details for their summer ritual. They also are known to try out various males and should things get a little rough or one of those males would like to run off during the night, the gap stops them cold. Nothing gets past the gap. The nerve center has lists of members and files on each and dirt on each. It has countless servers filled with all kinds of information about all kinds of people.

Now, one added little tidbit to this. I mentioned two compounds. There is a tunnel between the entertainer compound and also a compound consisting of three homes built by a shell company of the company that is a huge part of the music festival. The three homes and the entertainer compound are probably a good half mile apart, maybe a touch more, but there is a fully lit cement tunnel much like you would see underneath a football stadium that runs between the two locations. It can easily fit several golf carts or small cars in the passageway. Escape route for performers or a way for them to enjoy something more ominous courtesy of the Bohemian Grove board."

If you want to see "the gap", the address of the Griffin estate is : 81345 Avenue 54, La Quinta, CA 92253