Seems I'm a bit late to the party, but my youngest is going through this process right now so I have lots of info.
I'm assuming that by "camp" you really mean "going to cool classes filled with lots of nerds and maybe even some cute girls." If that is the case, then you probably won't find any "camp" that does it. What you need is a summer program, likely run by a top 100 US college/university.
A large number of them offer high school programs during the summer. Some of them give you college credits (way cool!), while others don't. At 15yo, I think you should focus on finding a good program before considering whether credits are give. If you were older, I'd place a higher priority on the credits but you have time to get those.
All of these programs have competitive admission. That means you have to apply and be accepted. Many offer scholarships. Deadlines for them are in the next couple of months so you need to get a move on.
These programs widely vary in nature so be sure to do your research. Here are some examples that I happen to be familiar with (not recommending them, I can just describe them without researching them). Here is a comparison of two programs. Both provide on-campus housing with other high-school program students, and lots of evening and weekend social activities. The BU program is fairly typical while the Stanford one is rather unique.
- Boston University: Wide array of subjects. You take regular classes with other BU summer students (eg: you could be the only high school student in a class of 40 students). Must take ~8 credits (2 classes) for the ~6-week program.
- Stanford University: Has a program similar to BU's but also offers a series of 2-week, non-credit program. You take one class and are given a written appraisal when done. If the appraisal is good, it can be used for college admissions. The class has about 15~40 students, all in the same program. You live in a small dorm that only houses your classmates and your class's teaching assistants. Basically, you think about one subject, 24x7, for the two weeks. There's a formal lecture in the morning, taught by a full faculty member and then the afternoon is small groups and individual work done in your dorm (remember your teaching assistants are living with in your dorm). Looks like a wonderful 2-week geekfest. I wish they took people my age :-) They only offer about a dozen programs. I think this year they are offering several computer science ones (eg; AI) and all of them require some degree of programming skill. I think you spend most of your time with your classmates so if female company is important to you, you may want to contact the school to find out about the typical male-to-female ratios. While they may not be able to give you exact numbers, they will have good estimates as colleges carefully track these stats.
Something like 90% of the top 100 universities have programs like BU's. My son went to BU last year and simply loved it. The Stanford program is the only one of its kind that I am aware of.
All of these programs really like taking non-American students as they like to brag about how many countries were represented in their summer program for the previous year. While you still need to apply to these programs, being non-American will likely give you a bit of a boost.
Hope this helps,
Neil
PS: You can use http://colleges.usnews.rankingsandreviews.com/best-colleges/rankings/national-universities for the list of best colleges. I'm not sure it's the best list, but it is easy to find and good enough to point you at the summer programs.