It is winter but the leaves are still on the ground. The playground is surrounded by a small wood in a city park. The fence around the playground is made from railroad ties and you can easily step over the fence, and they do; kids do not necessarily come in through the doors.

Sam arrives at the playground and steps over the fence. He spots Pete, the playworker, and he jumps and hugs him. Sam is 15 years old. He grew up at the playground and now volunteers as a playground helper. Sam and Pete sit down with the other staff around a wooden table and drink some tea.

Children start arriving at the playground, and they call from the window. Sam runs to the window, "Hello Beth!"

"I would like some nails and a hammer," she says and hands Sam her bike key. He puts the bike key with a Lego pirate, a sparkly bracelet, and other irreplaceable childhood possessions.

"Here you go," he replies. Beth is 10 years old with shoulder length brown hair. She's short for her age, and everyone thinks she is seven or eight. Beth comes inside with Matt. Matt is 9 years old and lives a couple of blocks from Beth.

"Pete! Pete!" she says, "Come play with us!" More kids surround Pete. Pete chases them out the door, and they run out of the building and jump onto a big cushy mat covered by a circus tent.

The kids bounce towards the edge of the mat and then hop back, tempt- ing Pete to see if he can catch them. They try to avoid being captured, but not too hard. If they get pulled off, then they get thrown high up in the air and back down onto the mat.

On the other side of the playground a cluster of children slip out between the fence where the water flows through. The water creates rivers through the leaves and the children lay planks across the water and attempt to walk across without getting wet. The water is only a couple of inches deep but it doesn't seem to matter; the game is in their imagination.

Beth spots Sam and she is excited to see him. They have been hanging out all week. "Come help me and my friend Matt build something," she says.

"Sure," says Sam. Sam, Beth and Matt discuss the possibilities.

"We could build a pirate ship," says Beth.

"...Or a house and then we could build furniture," says Matt.

"We should build a tree house and a ladder to climb into it," says Sam.

"...Or a post office," says Matt.

"Yeah! And then everyone could have mailboxes so their mail wouldn't get lost," says Beth.

"Yeah, and all the houses could have numbers so they know where to deliver the mail," says Matt.

"That would be so cool!" says Beth. "Let's do it."

"Okay, so what do we need?" wonders Sam.

"Hmmm, okay Matt, you get three hammers and some nails...I'll get the wood," says Beth.

"Where should we build it?" says Sam.

"In the center of all the forts and houses in the playground!" says Beth.

"Yeah, how 'bout next to Jaime and Molly's house?" asks Matt.

"Awesome," says Beth.

In a couple of minutes the carpenters meet up at the select spot carrying all the tools and wood. Sam has cleared "the lot" of a couple pieces of wood, a cart, and two tires. "Okay, Sam, you hold up that 4x4," says Beth. She starts to nail a 2x4 (2 inch by 4 inch piece of wood) onto the 4x4 to start the base of the building.

Matt calls to Pete, "Come over! We are building a post office."

"That is a great idea," says Pete, walking over.

"Pete, can you hold the other 4x4 up so I can nail it?" Pete holds the wood up and Matt nails the 2x4 to it. They raise all the corner posts and then begin nailing in strips of wood around the sides, starting from the bot- tom and moving up. Some of the pieces don't fit; they are too wide or too long, but they get nailed on just the way they are. They hammer at least one nail on each side of the boards. Sam says that it will be stronger if they put at least two nails on each side, so they do. They nail four 2x4's around the corner posts and then lay strips of wood across the roof and nail them on.

"Let me try standing on the roof," exclaims Matt. Matt jumps up and poses himself on top of the structure, grinning and laughing as the structure starts to sway slightly beneath him. "I guess we need to support this better," he yells "Ahh, I am coming down." He leaps off the roof as if it were a tall building, when in fact the post office is only 4 feet off the ground. "I made it," he says. "Lets go finish supporting the roof and the walls." It has been about 2 hours since they started the post office and the outside is almost done.

"This is awesome," decides Beth. "Tomorrow we can make a post office sign and decorate the inside." Beth, Matt, and Sam sit inside the Post Office discussing their lives, school, their dreams, and eventually get around to how the post office will work.

At the end of the day, Pete does not bother to close the gate. He says it is winter and there are not so many children. As we leave, Beth and Matt and some other kids consider the details of their new postal system.

"Bye, Pete," they all say.

"Bye," says Pete. He knows they will watch the playground.