Atomic bomb

I was at the bookstore earlier today and found a nice book about World War II. While browsing it, I found something that perplexed me. They stated that the code name for the test site where the first A-bomb was detonated was S-site. I have always understood that it was named Trinity site.

Could anyone use their expertise to help me verify this?. Also, does any of you know what criteria is used to assign those names? Thanks.

I wanted to feel the power between my legs–Rockhound, while sitting on the nuke, back on the asteroid.
Merry X-mas, and a happy new…Millenium!!!

This page refers to the “S-Site” and Trinity as separate facilities used by the Manhattan Project:

The official Los Alamos National Laboratory virtual tour says:

It sounds like it was part of the facilities used to develop the atomic bomb, but not the actual test site. From above, “S-Site” comes from “sawmill”; the origin of “Trinity” is evidently less clear; this web page gives a couple of possibilites:

Several other web sites say Oppenheimer chose the name.