The box is about 20 miles from downtown Houston going toward Galveston.  Follow I-45 South.  Exit on Bay Area Boulevard.  NOTE:  The address given in Atlas Quest is just to identify the correct general area of Houston.

Traveling east on Bay Area Blvd, four-tenths of a mile after you pass Park Shadows Trail, turn right into the park entrance. Once in the park watch for tennis courts on your right. Continue around the loop for three to four tenths of a mile.  [That's Armand Bayou on your left.]  On your right you will see
                                 20
prominently displayed.  Park at the last space before you reach the 20.  The letterbox is 15 paces almost due north (bearing 5) from the 20.  It's a well hidden, clear plastic container measuring about  5" x 5" x 2.5" 

This is a very active park, particularly on weekends.  It will be better to hunt this letterbox on weekdays.  You will have to be discrete to avoid exposing the box location.  After you have taken the box from its hiding place you can move to one of the nearby picnic tables to do your stamping.  It will be more convenient and, if there's no one close by, your activity probably won't attract attention. 

When I say this box is "kid friendly," I mean the location is -- someone may have to help small children find it and get it. 

If you find this letterbox, please use the "contact the placer" feature to tell to me its condition, and a little about your visit -- was it easy or hard to find?  were the instructions good?  did you like the box or hate it?  why?  was it hot, cold or raining?  did you meet any muggles or critters? etc, etc.  Thanks!