What are some fun things to do in your HUGE backyard?

You could do what I did, clear out a patch, cover it with gravel, throw down some lawn-furniture and you've got your forest living room. Go out there with a book and a lemonade when you want to relax and it's like Heaven. You don't need a very big gravel patch-the smaller the better-ideally just big enough around for a pair of Adirondack chairs and a small table.

You could maintain the trees. Trim the dead branches, keep the plants really healthy. You could also build a firepit in the back, and roast some marshmallows or just enjoy the smell of the wood. Or you could just take a walk in the woods, enjoy the nature; the sounds of the birds, the pretty moss growing on rocks, small animals, trees, bushes, and all that.

Here is what I do. Make a giant bubble wand out of a metal coat hanger. Then make your only bubble solution. 1/3 water to 2/3 dish washing detergent. Dip the wand in and run. Repeat until satisfied.

find a giant fish, like a boss

I will Climb trees and draw birds i see. Pretty fun and gets me connected to nature :)

well you could get some chairs and relax.get a pool. buy floweres to plant. get a little fountain to help relax. Play sports. Read a good book. have a party.

Well in a huge backyard you could get one of those outdoor benches and relax or you could start gardening and get heaps of flowers and make it not so much overgrown. I still find climbing trees fun so if you have any good trees climb em!

just sit out there, find a log and read, listen to music, or if you're a very focused person, just sit and listen. You can get some friends to come over and play an intense game of hide and seak, or just climb trees, take a walk, and i know its childish, but you could build a fort!

have a picnic, go hunting, build a treehouse, grow something...hehe