stem and medicine summer HS programs

What are some high school internships and highly selective summer programs relating to stem/medicine/neuroscience. Preferably no paid programs or programs that would not add much value to my education and college applications. Ive only been able to stumble upon SIMR and cni-x at stanford that I am really interested in for reference. I am going to be a junior this year and plan to attend these programs the summer before senior year.