....or a Bombshelter?

Growing up, I didn't really have a suitable tree for
a 'house'... But the Cuban Missile Crisis (1962)
apparently had quite an affect on me... I began dragging
huge wooden crates, partly balanced on my stateboard
(homemade), approx. 500 yards home from a manufacturing
Co., up the block and down an alley.

The crates were approx. 4'W x 6'L x 4' deep, and I snagged
two of them and lashed them together - I intended to stack
them 8' high in a hole I was digging.
I found a roll of tar paper and wrapped the unit up pretty well.

Well, my Mom alerted my Dad to what I was doing, and when he
came home I thought I was in trouble. Dad could see that this was
my way of dealing with any anxiety I was having about the 'crisis'-
anxiety I don't believe he was aware I was experiencing.

Well, to my relief and joy, he began helping me -
I definitely needed help dragging it over to the 7' deep hole I had
dug, and sliding/dropping it in. One foot would stick out of the
ground; covered with a wood top complete with trapdoor...
ala a 'bunker'.

Fortunately, we averted nuclear war and my 'shelter' became
a clubhouse until it was flooded by a cave-in on one side
after a particulary heavy rainstorm.

No clubhouse here. I had a few acres of woods that included tiny old car dump though.

I had a tree house except we called it a tree fort. It actually used four trees close together that made about a 10' square. It was only about 12' off the ground but it was enough so you had to use a rope ladder to get up in it.

We did have several small caves we use to play in also. They were in the out cropping of rocks. Biggest one only was about 12 or 14 feet deep and four or five feet wide but it made a great hideout. Our back yard and stream was a great place to trout fish and find arrowheads.

WOW... Sounds like you had a wonderful childhood.

An old dump of tiny cars or a tiny dump of old cars?

The older "kids" in our neighborhood stole wood from construction sites and built a three story house that started about thirty feet up a huge cottonwood. You came in via a trap door in the bottom floor and other trap doors led up, eventually, to a widow's walk on top of the third floor. We snuck up there a few times when they were not there. To get caught could have turned very bad very quickly. They were unpleasant sorts.
We also climbed everything from trees to water towers to Cooper's Rock Overlook (rocks the size of houses) with only our hands and (bare) feet. A girl fell 80' off of Cooper's Rock and now it's fenced off. She was drinking and climbing the wrong side. She lived but barely made it.
When I left home at fourteen I slept in steam tunnels to stay warm during the Winter. It's amazing that I survived much of those things that we did for fun.

From the late 40s to mid 50s (age 7-12) my brother and I built every form of hut and/or tree house imaginable.
We lived on the last un-paved road in our town... right across from a big field, and a small old non-working farm w/small apple orchard, abandoned chicken coops, corn cribs, a barn.. and a pasture and a really big woods.
This is where we spent our entire youth it seems.
We played in the trees and the brook and built huts and tree houses and "forts" everywhere.
Also go-carts or soap-box cars and what have you ....all the time... we were only indoors when it rained.

We had a tree-house, situated on the edge of town, that was about twenty to twenty-five feet up that we (the neighborhood gang) used to sleep in during the summer. That was about sixty years ago and the tree is gone now (sigh). It was next to a dirt road and I remember one summer night when a group of teenagers pulled up near the tree to drink and get rowdy. They weren't aware the tree-house was there and of course oblivious to our presence. We weren't about to get any sleep with them down there so we opened up on them with our b-b guns. They started hopping about and never figured out we were above them. They shouted some choice unprintable words and brought their little party to an abrupt halt and bolted out of there. Life was so simple then (and a lot more fun for the youths). I know, I know, someone is sure to say, "You could have shot someone's eye out". They were lucky I didn't carry my slingshot that night. Hey, it was a different world then.

No

We had disused "Anderson Shelters" in our back yard....

http://www.vauxhallandkennington.org.uk/shelter.shtml

...but then after WW2 we moved out to the country.

I tryed to build a clubhouse using the fence to hold it up because i didn't have a tree that would work but i had to take it down because it made the fence fall over. In a way i'm making up for it now by having a studio that only band members/close friends ov the band are allowed in.

Nick

We never got very far with tree houses (no suitable trees) but we did build huts. Of course it was more fun building and rebuilding them than actually using them for anything.

No tree house, but I had access both legal and illegal to many thousand acres of undeveloped land that ran between Dallas, Fort Worth and Arlington to ride dirt bikes in. Miles and miles of trails, hills and sand pits. Several motocross tracks and once a year a 250 mile enduro race came thru the area. I wasted SO much of my youth there.

Didn't everyone?

I had a club house I built under the big old apple tree. Added a second story to it later on. Slept in it at times too..... even wired up a wall switch, light and battery for lighting. Made scrap lumber & shingles from nearby new home construction. Even had a small fireplace in it and a downspout for the chimney. What a fun time that was and the new neighboring kids also built one, so we would visit back and forth between the two. Was a great place to hang out during rain, instead of going back in the house.

Many tree houses, a few caves, bb guns and sling shots. Fire shooters too. You take a spool of thread, lash a wide rubberband over one hole, shoot non-safety wooden matches like a sling shot after lighting them. We kept buckets of water around before doing this.

No tree forts here but there was a huge cement slab in the woods that we dug out underneath to make a fort. Our fort was overtaken by older kids. My buddy Bobby and I tried to take it back but received a sound beating for the attempt.

This is something I don't see kids these days doing. Playing in the woods. It's rare to even see a kid on the street.

The majority of my time as a kid was spent outside in one way or another. Playing in streams, down by the railroad tracks, under bridges, wherever.

While we didn't build a tree house, we hung out in a big apple tree in an overgrown field. Later the old two story house in front of the field became abandoned and we eventually got the nerve to go inside and explore.

In the partial basement I discovered a big hole beside the coal furnace duct and somehow got the courage to crawl in and check it out. It was a space under the whole first floor that was about 3 feet high and that became our secret clubhouse. We would hide in there with flashlights and candles until other kids would come into the house and we'd make spooky noises and hear their footsteps running out of the 'haunted house'

To this day I can't imagine how I overcame my fear enough to crawl into that dark hole in the basement, but we sure had some good times under that house!

Sort of.

We didn't have any trees that could support a treehouse, but we did have several large fruit trees that were suitable for climbing. We also had a small standalone workroom in the back yard, which was termite-ridden, dry rotted, and falling apart.

For the first few years we lived in that house, the outbuilding was primarily a play space for my model trains. However, my father grew increasingly concerned with the building's safety, and eventually took a sledgehammer to the entire structure.

He replaced it with what was unofficially dubbed the "stilt house." It was essentially a treeless treehouse--a wooden structure my dad designed and built, which sat one story off the ground supported by several braced and anchored 4x4 "legs." It had a large window on each of the broad sides, two small shuttered windows on one of the small side, and the fourth side had a doorway that opened onto a wooden bridge leading into the top of a grapefruit tree. There was also a trapdoor in the floor, with a retractable ladder. The door and the ladder were counterweighted so they would stay where you put them. As a result, you could climb in either from the ladder through the trapdoor, or through the tree to the "front" door.

That's what we had for most of my childhood. It was originally intended to be part of a much larger structure, but a combination of more-expensive-than-anticipated building materials and the fact that I was the only one using it (my brother got little use out of it, as it tended to attract bugs and spiders and he is allergic) led to a scaled back final design. My friends and I used it fairly regularly until I was a teenager, at which point it started getting used as a storage space instead. My parents are currently in the process of selling their house, and I have no idea whether or not the new owners will keep the structure.

I didn't have a tree house, but my dad bought me an old camper to play in. It was the style that slid in the back of a full size pickup. I had a stereo with record player and TV in there, because I ran an extension cord to the power jack and some old speaker wire to hook up the cable for the TV. If I remember right, I even ran a phone line out there too. I was pretty much on my own when I was little because there were few other kids within walking/biking distance, so I had to entertain myself.