Now to a teeny tiny door at the base of a tree that's created quite the mystery this morning. It has the internet burning up. Everybody wondering where it came from and whether there's anything... See More
Now to a teeny tiny door at the base of a tree that's created quite the mystery this morning. It has the internet burning up. Everybody wondering where it came from and whether there's anything magical on the o side. Abc's rob nelson is here. Is there anything magical on the other side? We don't know. That's the fun of the story. Pretty cool, good morning again, guys. This small little door has opened up imaginations in a big way out in san francisco. There are still plenty of questions about exactly where it came from but for right now visitors at this park are just letting themselves get caught up in the fun of it all. ♪ they can lead to a wonderland. I simply must get through. Reporter: To a candy coated fantasy. ♪ In a world of pure imagination ♪ Reporter: Or more simply just to a good old-fashioned cookie. It's that same sense of whimsy and magic that -- IT'S A DOOR. orter: -- That now have all eyes on this door in golden gate park in san francisco. I think it's fun for everyone to believe in a little magic. Reporter: Nobody knows exactly how or why the tiny wooden door came to be at the base of this elm tree but for visitors the door to their imagination is certainly wide open. Some leave notes. Do you really exist. Reporter: Others fantasize about the world on the door's other side. Maybe I could fit in there. I think it might have been fairies. Reporter: Perhaps wondering if they'll find peter pan's lost boys playing inside. ♪ Reporter: The door has unhinged a ton of response online, as well. It's art by someone with a whimsical spirit. I love it one resident wrote on a local blog. Another chimed in, I know with a bit of remodeling work it'll fetch 2200 per month. Park officials have no plans to, well, close the door on the area's latest attraction. We like children. We like elves. We like noms. We like butterflies. We like everything that encouraging people to have a good time so we'll probably leave it. Reporter: Plus who would have the heart to evict those adorable keebler elves? Oh, yeah. Now, o little boy believes a gnome lives behind and says do you really exist, do you really have magic in you if these questions are yes, write back. If no, I don't want to hear it. You need a little bit of magic every now and then. What a fun story. All right, rob, thank you.
This transcript has been automatically generated and may not be 100% accurate.