Most Helpful Guy
Your parents just try to be protective of you and thinking for your safety.
Well, you must just try communicate with them, convince them that you are enough responsible and you can control the situation. you are under eighteen and it is under eighteen party so it suits easily. try to develop conditions and agreement with your parents. remember! (sneaking is not a good option at all) so remind them you are reasonable enough to discuss this matter like a real mature person instead of sneaking or such behaviors which many teenagers do. it's a positive point of view that could impress them as well, then, ask them for their full reasoning. if they believe it is not safe, what factors are there which makes them to feel unsafe about it? is it the boys? is it the environment? is it that they believe there are bad influenced friends there? is it the long distance of the location? what exactly! then for those reasons you offer a solution and ask them to help you develop such solutions and come up with ideas for the pointed issues so as the result they could feel much safer and under control of the security of their daughter. besides, remind them how exciting it is for you and it's an experience of a lifetime and you would like to not miss this experience. so ask for their help with full honesty. and you can also use trading deals. for instance, if they let you go the party, you would help your mother on something for a week, or you will listen to whatever they say with no question for a period of time. or you will take a certain responsibility in order to replay to this favor. in the other hand, you must win psychologically, expression is important! express that you are aware of the possible risks, you are aware of their concern and you are appreciate it that they are trying to protect you as parents and you seeing and value their protective attitudes but also in the same time they must try to understand your feelings and willingness about how important the experience is for you and make this request to try find a way to make it work.
Wish you luck!