What are the most intense academic programs in US colleges?

I've always enjoyed challenging myself acadically, and I am thinking about pursuing a difficult major. From your experiences or what you've heard, what are some of the most intense academic programs in US colleges?

In the United States, a couple of programs with a reputation for being academically intense and rigorous include:

1. Massachusetts Institute of Technology (MIT) - Almost all programs at MIT are known for their intensity, particularly the engineering and computer science programs. The school's overall focus on technology and innovation results in a highly demanding academic atmosphere.

2. University of Chicago - It has a core curriculum that offers intense courses in the humanities and social sciences, and is known for rigorous academics across all disciplines. The economics program, in particular, is notoriously difficult.

3. California Institute of Technology (Caltech) - Like MIT, Caltech's science and engineering programs are infamous for their rigor. The school has a low student-to-faculty ratio, which provides an intensive focus on research.

4. Princeton University - The workload at Princeton, particularly within its engineering programs and in quantitative disciplines like economics and mathematics, is known to be very heavy. The university also has a unique undergraduate focus among Ivy League schools, which can add to the academic intensity.

5. Johns Hopkins University - Known especially for its pre-med and engineering programs. The programs are not only rigorous but students also compete with each other due to the grading curve used in some departments and the research-intensive environment.

6. Columbia University - Columbia's Core Curriculum is famously rigorous, with a heavy reading and writing workload. Many majors in the humanities and social sciences, including English and History, are known to be intense.

Please remember that a program's intensity can be highly individual, depending on your background, skill set, and ability to manage your time and stress. It's great to want to challenge yourself, but make sure you also consider the type of college experience you want and how these rigorous programs might impact that.