Mars and Island One

Here's a site that reviews movies for their physics quality:

http://www.intuitor.com/moviephysics/

Armageddon was rated "XP" (worst rating) - here's the commentary:
http://www.intuitor.com/moviephysics/armageddon.html

Their review of "The Core", also rated "XP", is also relevant and
entertaining:
http://www.intuitor.com/moviephysics/core.html

Details of how underground nuclear testing was done are available here:
http://www.globalsecurity.org/wmd/systems/nuke-testing.htm

I'll quote briefly:
Various methods are used for emplacing nuclear test devices so
that the ensuing explosion is contained. The most common method is to
emplace a test device at the bottom of a vertically drilled hole.
Another method is to emplace a test device within a tunnel that has
been mined horizontally to a location that is sufficiently deep to
provide containment.
[...]
The hole is then drilled using standard NTS big-hole drilling
techniques. A normal hole is from 1 to 3 meters (m) (48 to 120 inches
[in.]) diameter and from 213 to 762 meters (m) (600 to 2,500 feet [ft])
deep. During drilling, samples of drill cuttings are collected at 3-m
(10-ft) intervals, and rock cores are taken as required.

Arthur