Giant attack snail movie

[bjjohns]

OK, it's black and white, probably a 50's film. Giant attack snails would sneak up on people.

Things I am maybe on:
Snails may or may not have been radioactive
There might have been a dam involved.

[Shadow]

Try The Monster that Challenged the World.

http://www.badmovies.org/movies/monsterworld/

That might be it.

[Cult Movie Mania]

Could be The Creeping Terror.

[Andrew]

"The Monster that Conquered the World" would also be my guess.  The creatures have large snail shells.  They sneak up on one old guy in a dark scene, and the canal and lock system of the local waterway figures prominently.