The adirondack park includes new york’s forest preserve in upstate new york, united states. the park’s boundary corresponds to the adirondack mountains.. Custom designed gazebo plan package the complete gazebo plan & woodworking guides set, by adv plans, llc. tons of custom designed gazebo plans in. (shed shown is a 10×20 saltbox, built from our plans) the below pics were sent to us by a customer who built the 12×20 shed from our plans:.