Replying to Hidden Passages at your school

So today one of my buddies tells me that our school has a secret tunnel that goes from one building to the other and I'm like yeah right no way. So my friends and I spend our lunch period looking for it and find nothing. Then I tell this to one of my other friends who shows me where it is. It was like this little vent that has a ladder when you open it. I thought it was sick. We're gonna go through it tomorrow and see if it really goes to the other buidling. Its like something out of harry potter. Does anyone else have anything like this at their school most of the old ones with bomb shelters probably do.