I voted 'yes'.
We actually had 2 parties for him. I live in another country than my parents, so about 3 weeks before his first birthday I visited my parents and we had a party (with mostly my friends/family, only 2 other children) with lunch, cake, balloons, and presents for my LO. Approx. 20 people total.
On his actual birthday, we invited family and friends (including about 10 other kids) and had a party all afternoon/evening. We had a BBQ in our back yard, had a little pool set up and some toys out for the kids. My LO was napping for the first couple of hours but then we brought him down, gave him a cupcake and he opened gifts and played with the other kids. There were about 40 people who came to this one.
I thought it was fun to throw my LO a party, and he enjoyed all the attention and opening the gifts. That being said he remembers absolutely nothing of it now so it was really more for me (and the pictures!) than for him
He's turning 2 in a few weeks and we're doing something similar again, inviting about 50 people (including about 15 other kids) and will have different 'play stations' set up outside where kids can either slide, play in a ball pit, blow some bubbles, or colour some pictures.
Aside from all of the people coming, it's relatively low cost and will be just as much fun for DH and I as for DS.
But that's just what we're doing
I absolutely agree with everyone else, that whatever you decide to do with your LO will be great and a trip to the zoo sounds fun! My DS would love that just as much!