what field does architecture fall into and what universities and colleges major in it?

Answer 1

Architecture is its own field -- though you sometimes see it offered within a school of design.

It is offered at most of the large universities. Liberal arts colleges do not usually have a school of architecture.

Answer 2

It's a science more than an art. You do need the design sense, which is art, but you also need to know and understand load factors, the transfer of loads, the basics of plumbing, electrical and HVAC design and I'm sure more than a bit about soil sciences. Architecture is engineering combined with practical knowledge and visual design skills.