Not OP but omg I love the Embassy Suites sleepover idea! How many kids do you invite to that kind of a sleepover? Will have to bank that idea ...

Is he into video games? AJAX is fun if you want something easy and indoors.

There were some really great ideas on this blog post that would work for a birthday party. I love the idea of the night slides at Chesapeake MD

http://www.dcurbanmom.com/weblog/2012/07/05/dc-summer-activities-for-kids-a-to-z

Embassy Suites in dupont circle. My ds loves having his bday sleepover there. We bring his PS3 and have all the boys bring their handheld devices. They hit the pool first and then I give everyone quarters for the game room. Next we head pack to the room for pizza and cake and then the boys play video games the rest of the night. Its all their fav thingd. Oh and the breakfast buffet in the morning is amazing!

I have parents drop off and pick up from the hotel and order pizza when I get there. All I have to bring is the cake and quarters. Its a win win!

Woodworking at the Lowell School.

http://www.lowellschool.org/community-programs/birthday-parties/woodworking-parties/index.aspx

Movie theatre with a bunch of friends.

Nats game, sit in the cheaper seats.

OP here. That water park is Cameron Run. We went there the first day that school let out for summer. I actually suggested to have his bday party there but he didn't want to. That being said, my kids had a great time at the park and keep asking to go back. Plus, it's very reasonably priced.

Keep any other ideas coming. Thanks.

Water park? My DC went to one at the park in Alexandria and really liked it. They also have batting cages, i think.

I was going to suggest a minor league bball game (really inexpensive compared to the Nats), but maybe a Nats game would be better since you live in DC. My son went to a Potomac Nationals game for a bday party and he had a blast.

Live in Cap Hill.

Where do you live?

Try the Spy Museum

Does he like LEGOs? The Brick Fair is out at Dulles the first weekend in August and you could bring him and some friends to that, and give a Pick-a-Brick collection as goodie bags.

My son is turning 10 in August and I would like to have a special party for him. However, I'm stumped for new ideas. He's into baseball but not really interested in that type of party. We've done the sleepover, six flags, laser tag, etc... parties. Any fresh ideas out there?