For all of those turning 30 this year, attendance at the National Aquarium in Baltimore will be only $5 on Monday.
All you have to do is show your ID with a birth year of 1981 — same as the aquarium’s — and your general admission is $5.
Tickets ordinarily cost $24.95 for adults and $19.95 for children. You can check out the attraction’s birthday celebration events going on Friday through Monday here.